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Takamizawa R, Hotta K, Fujii Y, Ikegami R, Hitosugi N, Inoue T, Tamiya H, Tsubaki A. Transcapillary PO 2 Gradients in Contracting Muscles of Type I Diabetic Rats. Microcirculation 2024:e12870. [PMID: 38805591 DOI: 10.1111/micc.12870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 05/04/2024] [Accepted: 05/13/2024] [Indexed: 05/30/2024]
Abstract
OBJECTIVE This study aimed to clarify the effect of Type I diabetes (DIA) on transcapillary PO2 gradients, which are oxygen-driving factors between the blood and the interstitium, in the contracting muscle of rats. METHODS Wistar male rats were divided into the diabetic (streptozocin i.p.) and sham groups. Microvascular and interstitial PO2 were measured in the extensor digitorum longus muscle during electrical stimulation-induced muscle contraction, using the phosphorescence quenching method. Transcapillary PO2 gradient, ΔPO2, was calculated as microvascular minus interstitial PO2. RESULTS Resting microvascular PO2 was higher in the diabetic group than in the sham group (6.3 ± 1.7 vs. 4.7 ± 0.9 mmHg, p < 0.05) and remained for 180 s. Interstitial PO2 from rest to muscle contraction did not differ between the groups. The ΔPO2 was higher in the diabetic group than in the sham group at rest and during muscle contraction (4.03 ± 1.42 vs. 2.46 ± 0.90 mmHg at rest; 3.67 ± 1.51 vs. 2.22 ± 0.65 mmHg during muscle contraction, p < 0.05). Marked muscle atrophy was observed in the diabetic group. CONCLUSION DIA increased microvascular and transcapillary PO2 gradients in the skeletal muscle. The enhanced PO2 gradients were maintained from rest to muscle contraction in diabetic muscle.
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Affiliation(s)
- Ren Takamizawa
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan
| | - Kazuki Hotta
- Department of Rehabilitation, Kitasato University School of Allied Health Sciences, Sagamihara, Kanagawa, Japan
- Department of Rehabilitation Sciences, Kitasato University Graduate School of Medical Sciences, Sagamihara, Kanagawa, Japan
| | - Yutaka Fujii
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan
| | - Ryo Ikegami
- Department of Engineering Science, University of Electro-Communications, Chofu, Tokyo, Japan
| | - Naoki Hitosugi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan
| | - Tatsuro Inoue
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan
| | - Hajime Tamiya
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan
| | - Atsuhiro Tsubaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan
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Goliniewski J, Czuba M, Płoszczyca K, Chalimoniuk M, Gajda R, Niemaszyk A, Kaczmarczyk K, Langfort J. The Impact of Normobaric Hypoxia and Intermittent Hypoxic Training on Cardiac Biomarkers in Endurance Athletes: A Pilot Study. Int J Mol Sci 2024; 25:4584. [PMID: 38731803 PMCID: PMC11083773 DOI: 10.3390/ijms25094584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/15/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
This study explores the effects of normobaric hypoxia and intermittent hypoxic training (IHT) on the physiological condition of the cardiac muscle in swimmers. Hypoxia has been reported to elicit both beneficial and adverse changes in the cardiovascular system, but its impact on the myocardium during acute exercise and altitude/hypoxic training remains less understood. We aimed to determine how a single bout of intense interval exercise and a four-week period of high-intensity endurance training under normobaric hypoxia affect cardiac marker activity in swimmers. Sixteen young male swimmers were divided into two groups: one undergoing training in hypoxia and the other in normoxia. Cardiac markers, including troponin I and T (cTnI and cTnT), heart-type fatty acid-binding protein (H-FABP), creatine kinase-MB isoenzyme (CK-MB), and myoglobin (Mb), were analyzed to assess the myocardium's response. We found no significant differences in the physiological response of the cardiac muscle to intense physical exertion between hypoxia and normoxia. Four weeks of IHT did not alter the resting levels of cTnT, cTnI, and H-FABP, but it resulted in a noteworthy decrease in the resting concentration of CK-MB, suggesting enhanced cardiac muscle adaptation to exercise. In contrast, a reduction in resting Mb levels was observed in the control group training in normoxia. These findings suggest that IHT at moderate altitudes does not adversely affect cardiac muscle condition and may support cardiac muscle adaptation, affirming the safety and efficacy of IHT as a training method for athletes.
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Affiliation(s)
- Jakub Goliniewski
- Department of Sports Theory, The Jerzy Kukuczka Academy of Physical Education, 40-065 Katowice, Poland; (J.G.); (J.L.)
| | - Miłosz Czuba
- Faculty of Rehabilitation, Józef Piłsudski University of Physical Education in Warsaw, 00-968 Warsaw, Poland; (K.P.); (A.N.); (K.K.)
| | - Kamila Płoszczyca
- Faculty of Rehabilitation, Józef Piłsudski University of Physical Education in Warsaw, 00-968 Warsaw, Poland; (K.P.); (A.N.); (K.K.)
| | - Małgorzata Chalimoniuk
- Department of Tourism and Health in Biała Podlaska, The Józef Piłsudski University of Physical Education, 00-968 Warsaw, Poland;
| | - Robert Gajda
- Department of Kinesiology and Health Prevention, Jan Dlugosz University, 42-200 Czestochowa, Poland;
- Center for Sports Cardiology at the Gajda-Med Medical Center in Pultusk, 06-100 Pultusk, Poland
| | - Adam Niemaszyk
- Faculty of Rehabilitation, Józef Piłsudski University of Physical Education in Warsaw, 00-968 Warsaw, Poland; (K.P.); (A.N.); (K.K.)
| | - Katarzyna Kaczmarczyk
- Faculty of Rehabilitation, Józef Piłsudski University of Physical Education in Warsaw, 00-968 Warsaw, Poland; (K.P.); (A.N.); (K.K.)
| | - Józef Langfort
- Department of Sports Theory, The Jerzy Kukuczka Academy of Physical Education, 40-065 Katowice, Poland; (J.G.); (J.L.)
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Farra SD, Jacobs I. Arterial desaturation rate does not influence self-selected knee extension force but alters ventilatory response to progressive hypoxia: A pilot study. Physiol Rep 2024; 12:e15892. [PMID: 38172088 PMCID: PMC10764295 DOI: 10.14814/phy2.15892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024] Open
Abstract
The absolute magnitude and rate of arterial desaturation each independently impair whole-body aerobic exercise. This study examined potential mechanisms underlying the rate-dependent relationship. Utilizing an exercise protocol involving unilateral, intermittent, isometric knee extensions (UIIKE), we provided sufficient reperfusion time between contractions to reduce the accumulation of intramuscular metabolic by-products that typically stimulate muscle afferents. The objective was to create a milieu conducive to accentuating any influence of arterial desaturation rate on muscular fatigue. Eight participants completed four UIIKE sessions, performing one 3 s contraction every 30s at a perceived intensity of 50% MVC for 25 min. Participants voluntarily adjusted their force generation to maintain perceptual effort at 50% MVC without feedback. Reductions in inspired oxygen fraction (FI O2 ) decreased arterial saturation from >98% to 70% with varying rates in three trials: FAST (5.3 ± 1.3 min), MED (11.8 ± 2.7 min), and SLOW (19.9 ± 3.7 min). FI O2 remained at 0.21 during the control trial. Force generation and muscle activation remained at baseline levels throughout UIIKE trials, unaffected by the magnitude or rate of desaturation. Minute ventilation increased with hypoxia (p < 0.05), and faster desaturation rates magnified this response. These findings demonstrate that arterial desaturation magnitude and rate independently affect ventilation, but do not influence fatigue development during UIIKE.
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Affiliation(s)
- Saro D. Farra
- Faculty of Kinesiology & Physical EducationUniversity of TorontoTorontoOntarioCanada
| | - Ira Jacobs
- Faculty of Kinesiology & Physical EducationUniversity of TorontoTorontoOntarioCanada
- Tanenbaum Institute for Science in Sport, University of TorontoTorontoOntarioCanada
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Yao Y, Niu X. Construction of a physical fitness evaluation index system and model for high-level freestyle skiing aerials athletes in China. PLoS One 2023; 18:e0295622. [PMID: 38064528 PMCID: PMC10707543 DOI: 10.1371/journal.pone.0295622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
OBJECTIVE This study aims to enhance the competitive level of Chinese freestyle skiing aerials athletes by developing a specialized physical fitness evaluation index system and model tailored for high-level Chinese athletes. This system intends to provide theoretical references and training monitoring schemes in preparation for the 25th Milan Winter Olympics. METHODS A study was conducted on 29 high-level Chinese freestyle skiing aerials athletes. Physical fitness test indexes were selected using a literature review, expert interviews, and questionnaire surveys, and athletes were tested. Athletes were ensured to be in optimal physical condition before testing. Based on the test results, the representative indexes of the evaluation system are finally determined by combining R-type clustering analysis, multiple linear regression analysis. Determine index weights through weight questionnaires and normalization, and develop evaluation standards through methods such as percentile counting and weighted scoring. RESULTS Physical fitness evaluation system for Chinese freestyle skiing aerialists includes three aspects: evaluation index, index weight, and evaluation standard. The evaluation indexes include 3 first-level, 11 second-level, and 11 third-level indexes of body form, physiological function, and physical quality. In the evaluation weight, physical quality is ranked first, and physiological function and body form rank second and third, respectively. The evaluation standard consists of a scoring evaluation standard and a rating evaluation standard. Based on the index system, this study constructs the general and ideal physical fitness model of China's high-level freestyle aerials athletes. CONCLUSION The constructed physical fitness evaluation system effectively represents physical fitness development status of high-level freestyle skiing aerials athletes, providing a basis for creating personalized training plans. The established model serves as a reference for athletes' physical fitness development objectives.
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Affiliation(s)
- Youwei Yao
- School of Sports Training, Shenyang Sport University, Shenyang, China
| | - Xuesong Niu
- School of Social Sports, Shenyang Sport University, Shenyang, China
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Thurston TS, Weavil JC, Georgescu VP, Wan HY, Birgenheier NM, Morrissey CK, Jessop JE, Amann M. The exercise pressor reflex - a pressure-raising mechanism with a limited role in regulating leg perfusion during locomotion in young healthy men. J Physiol 2023; 601:4557-4572. [PMID: 37698303 PMCID: PMC10592099 DOI: 10.1113/jp284870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 08/15/2023] [Indexed: 09/13/2023] Open
Abstract
We investigated the role of the exercise pressor reflex (EPR) in regulating the haemodynamic response to locomotor exercise. Eight healthy participants (23 ± 3 years,V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ : 49 ± 6 ml/kg/min) performed constant-load cycling exercise (∼36/43/52/98%V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ ; 4 min each) without (CTRL) and with (FENT) lumbar intrathecal fentanyl attenuating group III/IV locomotor muscle afferent feedback and, thus, the EPR. To avoid different respiratory muscle metaboreflex and arterial chemoreflex activation during FENT, subjects mimicked the ventilatory response recorded during CTRL. Arterial and leg perfusion pressure (femoral arterial and venous catheters), femoral blood flow (Doppler-ultrasound), microvascular quadriceps blood flow index (indocyanine green), cardiac output (inert gas breathing), and systemic and leg vascular conductance were quantified during exercise. There were no cardiovascular and ventilatory differences between conditions at rest. Pulmonary ventilation, arterial blood gases and oxyhaemoglobin saturation were not different during exercise. Furthermore, cardiac output (-2% to -12%), arterial pressure (-7% to -15%) and leg perfusion pressure (-8% to -22%) were lower, and systemic (up to 16%) and leg (up to 27%) vascular conductance were higher during FENT compared to CTRL. Leg blood flow, microvascular quadriceps blood flow index, and leg O2 -transport and utilization were not different between conditions (P > 0.5). These findings reflect a critical role of the EPR in the autonomic control of the heart, vasculature and, ultimately, arterial pressure during locomotor exercise. However, the lack of a net effect of the EPR on leg blood flow challenges the idea of this cardiovascular reflex as a key determinant of leg O2 -transport during locomotor exercise in healthy, young individuals. KEY POINTS: The role of the exercise pressor reflex (EPR) in regulating leg O2 -transport during human locomotion remains uncertain. We investigated the influence of the EPR on the cardiovascular response to cycling exercise. Lumbar intrathecal fentanyl was used to block group III/IV leg muscle afferents and debilitate the EPR at intensities ranging from 30% to 100%V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ . To avoid different respiratory muscle metaboreflex and arterial chemoreflex activation during exercise with blocked leg muscle afferents, subjects mimicked the ventilatory response recorded during control exercise. Afferent blockade increased leg and systemic vascular conductance, but reduced cardiac output and arterial-pressure, with no net effect on leg blood flow. The EPR influenced the cardiovascular response to cycling exercise by contributing to the autonomic control of the heart and vasculature, but did not affect leg blood flow. These findings challenge the idea of the EPR as a key determinant of leg O2 -transport during locomotor exercise in healthy, young individuals.
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Affiliation(s)
- Taylor S. Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT
| | - Joshua C. Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, UT
| | - Vincent P. Georgescu
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT
| | - Hsuan-Yu Wan
- Department of Anesthesiology, University of Utah, Salt Lake City, UT
| | | | | | - Jacob E. Jessop
- Department of Anesthesiology, University of Utah, Salt Lake City, UT
| | - Markus Amann
- Department of Anesthesiology, University of Utah, Salt Lake City, UT
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, UT
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McClean ZJ, Zhang J, Khaledi N, Yacoub M, Aboodarda SJ. Intermittent blood flow occlusion modulates neuromuscular, perceptual, and cardiorespiratory determinants of exercise tolerance during cycling. Eur J Appl Physiol 2023; 123:2295-2306. [PMID: 37278835 DOI: 10.1007/s00421-023-05242-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/26/2023] [Indexed: 06/07/2023]
Abstract
PURPOSE Constant blood flow occlusion (BFO) superimposed on aerobic exercise can impair muscle function and exercise tolerance; however, no study has investigated the effect of intermittent BFO on the associated responses. Fourteen participants (n = 7 females) were recruited to compare neuromuscular, perceptual, and cardiorespiratory responses to shorter (5:15s, occlusion-to-release) and longer (10:30s) BFO applied during cycling to task failure. METHODS In randomized order, participants cycled to task failure (task failure 1) at 70% of peak power output with (i) shorter BFO, (ii) longer BFO, and (iii) no BFO (Control). Upon task failure in the BFO conditions, BFO was removed, and participants continued cycling until a second task failure (task failure 2). Maximum voluntary isometric knee contractions (MVC) and femoral nerve stimuli were performed along with perceptual measures at baseline, task failure 1, and task failure 2. Cardiorespiratory measures were recorded continuously across the exercises. RESULTS Task failure 1 was longer in Control than 5:15s and 10:30s (P < 0.001), with no differences between the BFO conditions. At task failure 1, 10:30s elicited a greater decline in twitch force compared to 5:15s and Control (P < 0.001). At task failure 2, twitch force remained lower in 10:30s than Control (P = 0.002). Low-frequency fatigue developed to a greater extent in 10:30s compared to Control and 5:15s (P < 0.047). Dyspnea and Fatigue were greater for Control than 5:15s and 10:30s at the end of task failure 1 (P < 0.002). CONCLUSION Exercise tolerance during BFO is primarily dictated by the decline in muscle contractility and accelerated development of effort and pain.
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Affiliation(s)
- Zachary John McClean
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, AB, T2N 1N4, Canada
| | - Jenny Zhang
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, AB, T2N 1N4, Canada
| | - Neda Khaledi
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, AB, T2N 1N4, Canada
- Faculty of Physical Education and Sport Sciences, Kharazmi University, Tehran, Iran
| | - Matthew Yacoub
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, AB, T2N 1N4, Canada
| | - Saied Jalal Aboodarda
- Faculty of Kinesiology, University of Calgary, 2500 University Dr NW, Calgary, AB, T2N 1N4, Canada.
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Yoon S, Lefrançois-Daignault T, Côté JN. The Effect of Cycling While Typing on Patterns of Upper Body Muscle Activation. HUMAN FACTORS 2023; 65:435-449. [PMID: 34078166 PMCID: PMC10152562 DOI: 10.1177/00187208211022147] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
OBJECTIVE To investigate the effect of one's sex and pedaling intensity on upper body muscle activation patterns during typing while cycling. BACKGROUND Females are at a higher risk for computer work-related musculoskeletal disorders, and mobile workstations have been suggested to induce healthier muscular patterns compared with sitting. However, the neuromuscular characteristics of performing computer work in a cycling workstation have not been investigated. METHOD Twenty-two participants (10 females) completed a 60-min computer typing task while pedaling on a cycle ergometer at two different intensities (25%, 4% heart rate reserve). Surface electromyography (EMG) was recorded from seven muscles of the upper body. Effects of time, sex, and intensity were assessed for muscle activation (RMS), activation variability (CV), and normalized mutual information (NMI) via generalized estimating equations. RESULTS With time, neck/shoulder CV increased in males during higher pedaling intensity, whereas in females it decreased during lower intensity. In females, RMS of neck/shoulder and NMI of neck/shoulder muscle pairs were lower, whereas forearm RMS was 34.2% higher with higher intensity cycling compared with lower intensity. Lower back RMS decreased 28.3% in the initial half of the task in females, but in males it increased 14.4% in the later half. CONCLUSION AND APPLICATION Cycling workstation showed a sex- and intensity-specific EMG response. These differing responses should be considered when implementing the use of cycling workstation and may be important for preventing/managing sex-specific muscle fatigue and musculoskeletal disorders.
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Affiliation(s)
- SangHoon Yoon
- McGill University, Montreal, Quebec, Canada
- Feil & Oberfeld/CRIR Research Center, Jewish Rehabilitation Hospital, Laval, Quebec, Canada
| | - Thierry Lefrançois-Daignault
- McGill University, Montreal, Quebec, Canada
- Feil & Oberfeld/CRIR Research Center, Jewish Rehabilitation Hospital, Laval, Quebec, Canada
| | - Julie N Côté
- McGill University, Montreal, Quebec, Canada
- Feil & Oberfeld/CRIR Research Center, Jewish Rehabilitation Hospital, Laval, Quebec, Canada
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Martínez-Noguera FJ, Alcaraz PE, Carlos-Vivas J, Marín-Pagán C. 8 weeks of 2 S-hesperidin prevents a decrease in pO 2 at submaximal intensity in amateur cyclists in off-season: randomized controlled trial. Food Funct 2023; 14:2750-2767. [PMID: 36857626 DOI: 10.1039/d2fo03007a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Although chronic supplementation with 2S-hesperidin has been shown to improve performance, to date, the possible mechanisms underlying this effect have not been explored. Therefore, the aim of this study was to assess whether changes in gasometry may be associated with improved performance after the intake of 2S-hesperidin (500 mg d-1, 8 weeks). Forty amateur cyclists (n = 20 2S-hesperidin, n = 20 placebo) performed a rectangular test, during which capillary blood samples were taken at the baseline, FatMax1, ventilatory threshold 1 and 2 (VT1 and VT2), power maximum (PMAX), FatMax2 and excess post-exercise O2 consumption (EPOC) to measure gasometry parameters. Significantly increased CO2 and tCO2 was found at FatMax1, VT1, FatMax2 and EPOC (p = <0.05) after 8 weeks of 2S-hesperidin ingestion. Conversely, the placebo group had a significant decrease in pO2 at VT2 (p = 0.04) during the rectangular test, with no changes in the 2S-hesperidin group. Therefore, chronic supplementation with 2S-hesperidin prevents decreases in pO2 at submaximal intensities in amateur cyclists in an off-season period.
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Affiliation(s)
- Francisco Javier Martínez-Noguera
- Research Center for High Performance Sport, Catholic University of Murcia, Campus de los Jerónimos N° 135, UCAM, 30107, Murcia, Spain.
| | - Pedro E Alcaraz
- Research Center for High Performance Sport, Catholic University of Murcia, Campus de los Jerónimos N° 135, UCAM, 30107, Murcia, Spain.
| | - Jorge Carlos-Vivas
- Health, Economy, Motricity and Education Research Group (HEME), Faculty of Sport Sciences, University of Extremadura, Avda. de Elvas, s/n., 06006, Badajoz, Spain.
| | - Cristian Marín-Pagán
- Research Center for High Performance Sport, Catholic University of Murcia, Campus de los Jerónimos N° 135, UCAM, 30107, Murcia, Spain.
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McClean ZJ, Young A, Pohl AJ, Fine NM, Burr JF, MacInnis M, Aboodarda SJ. Blood flow restriction during high-intensity interval cycling exacerbates psychophysiological responses to a greater extent in females than males. J Appl Physiol (1985) 2023; 134:596-609. [PMID: 36701480 DOI: 10.1152/japplphysiol.00567.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
This study aimed to characterize neuromuscular, perceptual, and cardiorespiratory responses to high-intensity interval training (HIIT) with superimposed blood flow restriction in males and females. Twenty-four, healthy individuals (n = 12 females) completed two cycling HIIT protocols to task failure (1-min work phases at 90% of peak power output interspersed by 1-min rest phases). The blood flow restriction (BFR) and control (CON) protocols were identical except for the presence and absence of BFR during rest phases, respectively. The interpolated twitch technique, including maximal voluntary isometric knee extension (MVC) and femoral nerve electrical stimuli, was performed at baseline, every six intervals, and task failure. Perceptual and cardiorespiratory responses were recorded every three intervals and continuously during exercise, respectively. Bayesian inference was used to obtain the joint posterior distribution for all parameters and evidence of an effect was determined via the marginal posterior probability (PP). The BFR shortened task duration by 57.3% compared with CON (PP > 0.99), without a sex difference. The application of BFR exacerbated the rate of decline in neuromuscular measures (MVC and twitch force output), increase of perceptual responses (perceived effort, pain, dyspnea, fatigue), and development of cardiorespiratory parameters (minute ventilation and heart rate), compared with CON (PP > 0.95). In addition, BFR exacerbated the neuromuscular, perceptual, and cardiorespiratory responses to a greater extent in females than males (PP > 0.99). Our results suggest that superimposition of blood flow restriction exacerbates psychophysiological responses to a HIIT protocol to a greater extent in females than males.NEW & NOTEWORTHY To our knowledge, no study has explored sex differences in the neuromuscular, perceptual, and cardiorespiratory indices characterizing exercise tolerance during high-intensity interval training (HIIT) with blood flow restriction (BFR) applied only during rest periods. Our results suggest that BFR elicited a decline in exercise performance that could be attributed to integration of psychophysiological responses. However, this integration was sex-dependent where females demonstrated an exacerbated rate of change in these responses compared with males.
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Affiliation(s)
- Zachary J McClean
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Abbey Young
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Andrew J Pohl
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Nowell M Fine
- Cummings School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jamie F Burr
- College of Biological Science, University of Guelph, Guelph, Ontario, Canada
| | - Martin MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Saied J Aboodarda
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
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Drouin PJ, Liu T, Lew LA, McGarity-Shipley E, Tschakovsky ME. The 'normal' adjustment of oxygen delivery to small muscle mass exercise is not optimized for muscle contractile function. J Physiol 2023; 601:783-799. [PMID: 36644910 DOI: 10.1113/jp283933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/04/2023] [Indexed: 01/17/2023] Open
Abstract
Oxygen delivery is viewed as tightly coupled to demand in exercise below critical power because increasing oxygen delivery does not increase V O 2 ${V_{{O_2}}}$ . However, whether the 'normal' adjustment of oxygen delivery to small muscle mass exercise in the heavy intensity domain is optimal for excitation-contraction coupling is currently unknown. In 20 participants (10 female), a remote skeletal muscle (i.e. tibialis anterior) metaboreflex was (Hyperperfusion condition) or was not (Control condition) activated for 4 min during both force of contraction (experimental model 1) and muscle activation-targeted (experimental model 2) rhythmic forearm handgrip exercise. Analysis was completed on the combined data from both experimental models. After 30 s of remote skeletal muscle metaboreflex activation, mean arterial blood pressure, forearm blood flow and muscle oxygenation were increased and remained increased until metaboreflex discontinuation. While oxygen delivery was elevated, the muscle activation to force of contraction ratio was improved. Upon metaboreflex discontinuation, forearm oxygen delivery and the muscle activation and force of contraction ratio rapidly (within 30 s) returned to control levels. These findings demonstrate that (a) the metaboreflex was effective at increasing forearm muscle oxygen delivery and oxygenation, (b) the muscle activation to force of contraction ratio was improved with increased oxygen delivery, and (c) in the heavy exercise intensity domain, the normal matching of oxygen delivery to metabolic demand is not optimal for muscle excitation-contraction coupling. These results suggest that the nature of vasoregulation in exercising muscle is such that it does not support optimal perfusion for excitation-contraction coupling. KEY POINTS: Oxygen delivery is viewed as tightly coupled to demand in exercise below critical power because increasing oxygen delivery does not increase the rate of oxygen uptake. Whether the 'normal' adjustment of oxygen delivery in small muscle mass exercise below critical power is optimal for excitation-contraction coupling is not known. Here we show in humans that increasing oxygen delivery above 'normal' improves excitation-contraction coupling. These results suggest that, in the heavy exercise intensity domain, the 'normal' matching of oxygen delivery to metabolic demand is not optimal for muscle excitation-contraction coupling. Therefore, the nature of vasoregulation in exercising muscle is such that it does not support optimal perfusion for excitation-contraction coupling.
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Affiliation(s)
- Patrick J Drouin
- Human Vascular Control Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Taylor Liu
- Human Vascular Control Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Lindsay A Lew
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Ellen McGarity-Shipley
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Michael E Tschakovsky
- Human Vascular Control Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
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The effect of constant load cycling at extreme- and severe-intensity domains on performance fatigability and its determinants in young female. Sci Sports 2023. [DOI: 10.1016/j.scispo.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Competition Between Desired Competitive Result, Tolerable Homeostatic Disturbance, and Psychophysiological Interpretation Determines Pacing Strategy. Int J Sports Physiol Perform 2023; 18:335-346. [PMID: 36848906 DOI: 10.1123/ijspp.2022-0171] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 11/22/2022] [Accepted: 12/19/2022] [Indexed: 03/01/2023]
Abstract
Scientific interest in pacing goes back >100 years. Contemporary interest, both as a feature of athletic competition and as a window into understanding fatigue, goes back >30 years. Pacing represents the pattern of energy use designed to produce a competitive result while managing fatigue of different origins. Pacing has been studied both against the clock and during head-to-head competition. Several models have been used to explain pacing, including the teleoanticipation model, the central governor model, the anticipatory-feedback-rating of perceived exertion model, the concept of a learned template, the affordance concept, the integrative governor theory, and as an explanation for "falling behind." Early studies, mostly using time-trial exercise, focused on the need to manage homeostatic disturbance. More recent studies, based on head-to-head competition, have focused on an improved understanding of how psychophysiology, beyond the gestalt concept of rating of perceived exertion, can be understood as a mediator of pacing and as an explanation for falling behind. More recent approaches to pacing have focused on the elements of decision making during sport and have expanded the role of psychophysiological responses including sensory-discriminatory, affective-motivational, and cognitive-evaluative dimensions. These approaches have expanded the understanding of variations in pacing, particularly during head-to-head competition.
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13
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Zhang Q, Haselden WD, Charpak S, Drew PJ. Could respiration-driven blood oxygen changes modulate neural activity? Pflugers Arch 2023; 475:37-48. [PMID: 35761104 PMCID: PMC9794637 DOI: 10.1007/s00424-022-02721-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/26/2022] [Accepted: 06/16/2022] [Indexed: 01/31/2023]
Abstract
Oxygen is critical for neural metabolism, but under most physiological conditions, oxygen levels in the brain are far more than are required. Oxygen levels can be dynamically increased by increases in respiration rate that are tied to the arousal state of the brain and cognition, and not necessarily linked to exertion by the body. Why these changes in respiration occur when oxygen is already adequate has been a long-standing puzzle. In humans, performance on cognitive tasks can be affected by very high or very low oxygen levels, but whether the physiological changes in blood oxygenation produced by respiration have an appreciable effect is an open question. Oxygen has direct effects on potassium channels, increases the degradation rate of nitric oxide, and is rate limiting for the synthesis of some neuromodulators. We discuss whether oxygenation changes due to respiration contribute to neural dynamics associated with attention and arousal.
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Affiliation(s)
- Qingguang Zhang
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - William D Haselden
- Medical Scientist Training Program, College of Medicine, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Serge Charpak
- Institut de La Vision, INSERM, CNRS, Sorbonne Université, Paris, France
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Patrick J Drew
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, 16802, USA.
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14
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Song Q, Cheng X, Zheng R, Yang J, Wu H. Effects of different exercise intensities of race-walking on brain functional connectivity as assessed by functional near-infrared spectroscopy. Front Hum Neurosci 2022; 16:1002793. [PMID: 36310841 PMCID: PMC9614086 DOI: 10.3389/fnhum.2022.1002793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/28/2022] [Indexed: 12/02/2022] Open
Abstract
Introduction Race-walking is a sport that mimics normal walking and running. Previous studies on sports science mainly focused on the cardiovascular and musculoskeletal systems. However, there is still a lack of research on the central nervous system, especially the real-time changes in brain network characteristics during race-walking exercise. This study aimed to use a network perspective to investigate the effects of different exercise intensities on brain functional connectivity. Materials and methods A total of 16 right-handed healthy young athletes were recruited as participants in this study. The cerebral cortex concentration of oxyhemoglobin was measured by functional near-infrared spectroscopy in the bilateral prefrontal cortex (PFC), the motor cortex (MC) and occipital cortex (OC) during resting and race-walking states. Three specific periods as time windows corresponding to different exercise intensities were divided from the race-walking time of participants, including initial, intermediate and sprint stages. The brain activation and functional connectivity (FC) were calculated to describe the 0.01-0.1 Hz frequency-specific cortical activities. Results Compared to the resting state, FC changes mainly exist between MC and OC in the initial stage, while PFC was involved in FC changes in the intermediate stage, and FC changes in the sprint stage were widely present in PFC, MC and OC. In addition, from the initial-development to the sprint stage, the significant changes in FC were displayed in PFC and MC. Conclusion This brain functional connectivity-based study confirmed that hemodynamic changes at different exercise intensities reflected different brain network-specific characteristics. During race-walking exercise, more extensive brain activation might increase information processing speed. Increased exercise intensity could facilitate the integration of neural signals such as proprioception, motor control and motor planning, which may be an important factor for athletes to maintain sustained motor coordination and activity control at high intensity. This study was beneficial to understanding the neural mechanisms of brain networks under different exercise intensities.
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Affiliation(s)
- Qianqian Song
- Capital University of Physical Education and Sports, Beijing, China
- School of Physical Education, Yanshan University, Qinhuangdao, China
| | - Xiaodong Cheng
- Capital University of Physical Education and Sports, Beijing, China
| | - Rongna Zheng
- School of Physical Education, Ludong University, Yantai, China
| | - Jie Yang
- School of Physical Education, Ludong University, Yantai, China
- Jie Yang,
| | - Hao Wu
- Capital University of Physical Education and Sports, Beijing, China
- *Correspondence: Hao Wu,
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15
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Drouin PJ, Forbes SPA, Liu T, Lew LA, McGarity-Shipley E, Tschakovsky ME. Muscle contraction force conforms to muscle oxygenation during constant activation voluntary forearm exercise. Exp Physiol 2022; 107:1360-1374. [PMID: 35971738 DOI: 10.1113/ep090576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/11/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? In electrically stimulated skeletal muscle, force production is downregulated when oxygen delivery is compromised and rapidly restored upon oxygen delivery restoration. Whether "oxygen conforming" of force production occurs during voluntary muscle activation in humans and whether it is exercise intensity dependent remains unknown. What is the main finding and its importance? Here we show in humans that force at a given voluntary muscle activation does conform to a decrease in oxygen delivery and rapidly and completely recovers with restoration of oxygen delivery. This oxygen conforming response of contraction force appears to happen only at higher intensities. ABSTRACT In electrically stimulated skeletal muscle, force production is downregulated when oxygen delivery is compromised and rapidly restored upon oxygen delivery restoration in the absence of cellular disturbance. Whether this "oxygen conforming" response of force occurs and is exercise intensity dependent during stable voluntary muscle activation in humans is unknown. In 12-participants (6-female), handgrip force, forearm muscle activation (electromyography; EMG), muscle oxygenation, and forearm blood flow (FBF) were measured during rhythmic handgrip exercise at forearm EMG achieving 50, 75 or 90% critical impulse (CI). 4-min of brachial artery compression to reduce FBF by ∼60% (Hypoperfusion) or sham compression (adjacent to artery; Control) was performed during exercise. Sham compression had no effect. Hypoperfusion rapidly reduced muscle oxygenation at all exercise intensities, resulting in contraction force per muscle activation (force/EMG) progressively declining over 4 min by ∼16% in 75 and 90% CI. No force/EMG decline occurred in 50% CI. Rapid restoration of muscle oxygenation post-compression was closely followed by force/EMG such that it was not different from Control within 30-sec for 90% CI and after 90-sec for 75% CI. Our findings reveal an oxygen conforming response does occur in voluntary exercising muscle in humans. Within the exercise modality and magnitude of fluctuation of oxygenation in this study, the oxygen conforming response appears to be exercise intensity dependent. Mechanisms responsible for this oxygen conforming response have implications for exercise tolerance and warrant investigation. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Patrick J Drouin
- Human Vascular Control Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Stacey P A Forbes
- Human Vascular Control Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Taylor Liu
- Human Vascular Control Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Lindsay A Lew
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Ellen McGarity-Shipley
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Michael E Tschakovsky
- Human Vascular Control Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
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16
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Hansen AB, Moralez G, Amin SB, Hofstätter F, Simpson LL, Gasho C, Tymko MM, Ainslie PN, Lawley JS, Hearon CM. Global REACH 2018: increased adrenergic restraint of blood flow preserves coupling of oxygen delivery and demand during exercise at high-altitude. J Physiol 2022; 600:3483-3495. [PMID: 35738560 PMCID: PMC9357095 DOI: 10.1113/jp282972] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 06/16/2022] [Indexed: 01/05/2023] Open
Abstract
Chronic exposure to hypoxia (high-altitude, HA; >4000 m) attenuates the vasodilatory response to exercise and is associated with a persistent increase in basal sympathetic nerve activity (SNA). The mechanism(s) responsible for the reduced vasodilatation and exercise hyperaemia at HA remains unknown. We hypothesized that heightened adrenergic signalling restrains skeletal muscle blood flow during handgrip exercise in lowlanders acclimatizing to HA. We tested nine adult males (n = 9) at sea-level (SL; 344 m) and following 21-28 days at HA (∼4300 m). Forearm blood flow (FBF; duplex ultrasonography), mean arterial pressure (MAP; brachial artery catheter), forearm vascular conductance (FVC; FBF/MAP), and arterial and venous blood sampling (O2 delivery ( DO2${D}_{{{\rm{O}}}_{\rm{2}}}$ ) and uptake ( V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ )) were measured at rest and during graded rhythmic handgrip exercise (5%, 15% and 25% of maximum voluntary isometric contraction; MVC) before and after local α- and β-adrenergic blockade (intra-arterial phentolamine and propranolol). HA reduced ΔFBF (25% MVC: SL: 138.3 ± 47.6 vs. HA: 113.4 ± 37.1 ml min-1 ; P = 0.022) and Δ V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ (25% MVC: SL: 20.3 ± 7.5 vs. HA: 14.3 ± 6.2 ml min-1 ; P = 0.014) during exercise. Local adrenoreceptor blockade at HA restored FBF during exercise (25% MVC: SLα-β blockade : 164.1 ± 71.7 vs. HAα-β blockade : 185.4 ± 66.6 ml min-1 ; P = 0.947) but resulted in an exaggerated relationship between DO2${D}_{{{\rm{O}}}_{\rm{2}}}$ and V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ ( DO2${D}_{{{\rm{O}}}_{\rm{2}}}$ / V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ slope: SL: 1.32; HA: slope: 1.86; P = 0.037). These results indicate that tonic adrenergic signalling restrains exercise hyperaemia in lowlanders acclimatizing to HA. The increase in adrenergic restraint is necessary to match oxygen delivery to demand and prevent over perfusion of contracting muscle at HA. KEY POINTS: In exercising skeletal muscle, local vasodilatory signalling and sympathetic vasoconstriction integrate to match oxygen delivery to demand and maintain arterial blood pressure. Exposure to chronic hypoxia (altitude, >4000 m) causes a persistent increase in sympathetic nervous system activity that is associated with impaired functional capacity and diminished vasodilatation during exercise. In healthy male lowlanders exposed to chronic hypoxia (21-28 days; ∼4300 m), local adrenoreceptor blockade (combined α- and β-adrenergic blockade) restored skeletal muscle blood flow during handgrip exercise. However, removal of tonic adrenergic restraint at high altitude caused an excessive rise in blood flow and subsequently oxygen delivery for any given metabolic demand. This investigation is the first to identify greater adrenergic restraint of blood flow during acclimatization to high altitude and provides evidence of a functional role for this adaptive response in regulating oxygen delivery and demand.
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Affiliation(s)
| | - Gilbert Moralez
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, TX, USA
| | - Sachin B. Amin
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Florian Hofstätter
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Lydia L. Simpson
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Christopher Gasho
- Department of Medicine, Division of Pulmonary and Critical Care, University of Loma Linda, Loma Linda, California, USA
| | - Michael M. Tymko
- Physical Activity and Diabetes Laboratory, Faculty of Kinesiology, Sport and Recreation, University of Alberta, Edmonton, AB, Canada.,Centre of Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia – Okanagan, Kelowna, British Columbia, Canada
| | - Philip N. Ainslie
- Centre of Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia – Okanagan, Kelowna, British Columbia, Canada
| | - Justin S. Lawley
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Christopher M. Hearon
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, TX, USA.,Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, TX, USA.,Correspondence: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, 7232 Greenville Avenue, Suite 435, Dallas, TX, 75231, USA.
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17
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McKeown DJ, McNeil CJ, Simmonds MJ, Kavanagh JJ. Post-fatigue ability to activate muscle is compromised across a wide range of torques during acute hypoxic exposure. Eur J Neurosci 2022; 56:4653-4668. [PMID: 35841186 PMCID: PMC9546238 DOI: 10.1111/ejn.15773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 06/11/2022] [Accepted: 07/13/2022] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to assess how severe acute hypoxia alters the neural mechanisms of muscle activation across a wide range of torque output in a fatigued muscle. Torque and electromyography responses to transcranial and motor nerve stimulation were collected from 10 participants (27 years ± 5 years, 1 female) following repeated performance of a sustained maximal voluntary contraction that reduced torque to 60% of the pre‐fatigue peak torque. Contractions were performed after 2 h of hypoxic exposure and during a sham intervention. For hypoxia, peripheral blood oxygen saturation was titrated to 80% over a 15‐min period and remained at 80% for 2 h. Maximal voluntary torque, electromyography root mean square, voluntary activation and corticospinal excitability (motor evoked potential area) and inhibition (silent period duration) were then assessed at 100%, 90%, 80%, 70%, 50% and 25% of the target force corresponding to the fatigued maximal voluntary contraction. No hypoxia‐related effects were identified for voluntary activation elicited during motor nerve stimulation. However, during measurements elicited at the level of the motor cortex, voluntary activation was reduced at each torque output considered (P = .002, ηp2 = .829). Hypoxia did not impact the correlative linear relationship between cortical voluntary activation and contraction intensity or the correlative curvilinear relationship between motor nerve voluntary activation and contraction intensity. No other hypoxia‐related effects were identified for other neuromuscular variables. Acute severe hypoxia significantly impairs the ability of the motor cortex to voluntarily activate fatigued muscle across a wide range of torque output.
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Affiliation(s)
- Daniel J McKeown
- Neural Control of Movement Laboratory, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Chris J McNeil
- Integrated Neuromuscular Physiology Laboratory, Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Michael J Simmonds
- Biorheology Research Laboratory, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Justin J Kavanagh
- Neural Control of Movement Laboratory, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
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18
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Mateo-March M, Muriel X, Valenzuela PL, Gandia-Soriano A, Zabala M, Barranco-Gil D, Pallarés JG, Lucia A. Altitude and Endurance Performance in Altitude Natives versus Lowlanders: Insights from Professional Cycling. Med Sci Sports Exerc 2022; 54:1218-1224. [PMID: 35142712 DOI: 10.1249/mss.0000000000002890] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Acute altitude exposure influences exercise performance, although most research, especially regarding altitude natives, comes from laboratory data in nonathletes. PURPOSE We analyzed the influence of altitude on real-world cycling performance in top-level professional cyclists attending to whether they were altitude natives or not. METHODS Thirty-three male cyclists (29 ± 5 yr) were studied and were classified as lowlanders (n = 19) or altitude natives (n = 14) attending to the altitude of their place of birth (431 ± 380 and 2583 ± 334 meters above sea level (m a.s.l.), respectively). Both groups included top 3 finishers (including winners) in the general classification of Grand Tours and major races. Using data from both training and competitions during years 2013-2020 (8 ± 5 seasons per cyclist), we registered participants' mean maximal power (MMP) for efforts lasting 5 s, 30 s, 5 min, and 10 min, respectively, at altitudes ranging from 0-500 to >2000 m a.s.l. RESULTS A significant altitude-MMP interaction effect (two-factor repeated-measures ANOVA) was found in lowlanders (P < 0.001) but not in altitude natives (P = 0.150). In lowlanders, individual performance decreased in a dose-response manner with increasing altitudes compared with sea (or near-sea) level (0-500 m a.s.l.), whereas this trend was much less evident in natives. A significant altitude-MMP-group effect was found (P < 0.001), with nonsignificant (and overall trivial-to-small differences) between lowlanders and altitude natives for any effort duration at altitudes ≤1500 m a.s.l. but with significant differences at higher altitudes (≥1501 m a.s.l.). CONCLUSIONS Acute altitude exposure influences real-world performance differently in low landers and altitude natives, which might confer a competitive advantage to the latter, particularly in races including efforts at >1500 m a.s.l.
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Affiliation(s)
| | - Xabier Muriel
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, SPAIN
| | - Pedro L Valenzuela
- Instituto de Investigación Hospital 12 de Octubre (imas12), Grupo de Investigación en Actividad Física y Salud (PaHerg), Madrid, SPAIN
| | - Alexis Gandia-Soriano
- Biophysics and Medical Physics Group (GIFIME), Department of Physiology, University of Valencia, Valencia, SPAIN
| | - Mikel Zabala
- Department of Physical Education & Sport, Faculty of Sport Sciences, University of Granada, Granada, SPAIN
| | | | - Jesús G Pallarés
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, SPAIN
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19
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Acute Physiological Response to Different Sprint Training Protocols in Normobaric Hypoxia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19052607. [PMID: 35270299 PMCID: PMC8909614 DOI: 10.3390/ijerph19052607] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/14/2022] [Accepted: 02/21/2022] [Indexed: 11/17/2022]
Abstract
BACKGROUND the purpose of this study was to examine acute physiological responses to and the performance effects of two sprint training protocols in normobaric hypoxic conditions. METHODS Healthy competitive female (n = 2) and male (n = 5) kayakers (19 ± 2.1 years) performed four sprint training sessions on a kayak ergometer over a period of two weeks. Participants performed five sets of 12 × 5 s sprints or 3 × 20 s sprints in both normobaric normoxic (NOR, FiO2 = 20.9%) or normobaric hypoxic (HYP, FiO2 = 13.6%) conditions. The peak power output (PPO), rate of perceived exertion (RPE), and heart rate (HR) of each participant were monitored continuously. Their blood lactate concentrations ([BLa+]), in addition to their blood gas (mixed-venous partial pressure (p) of carbon dioxide (pCO2), O2 (pO2), and oxygen saturations (sO2)) were collected before and after exercise. RESULTS A significantly greater RPE, HR, and [BLa+] response and a significant decrease in pCO2, pO2, and sO2 were observed in HYP conditions versus NOR ones, independent of the type of training session. The PPO of participants did not differ between sessions. Their RPE in HYP12 × 5 was greater compared to all other sessions. CONCLUSIONS The HYP conditions elicited significantly greater physiological strain compared to NOR conditions and this was similar in both training sessions. Our results suggest that either sprint training protocol in HYP conditions may induce more positive training adaptations compared to sprint training in NOR conditions.
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20
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Pycke JR, Billat V. Marathon Performance Depends on Pacing Oscillations between Non Symmetric Extreme Values. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19042463. [PMID: 35206654 PMCID: PMC8877899 DOI: 10.3390/ijerph19042463] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/02/2022] [Accepted: 02/05/2022] [Indexed: 02/04/2023]
Abstract
A marathon was recently run in less than 2 h by a man who ran the three fastest marathons ever recorded in a span of three years—Eliud Kipchoge—in the Tokyo Olympic games. Here, we demonstrate that the best marathons were run according to a pace distribution that is statistically not constant and with negative asymmetry. The concept of mirror race enables us to show that the sign of asymmetry is not due to sampling fluctuations. We show that marathon performance depends on pacing oscillations between extreme values, and that even the best marathons ever run differ and can be improved upon. The utilization of extreme values and oscillations allows for recovery and optimization of the complementary aerobic and anaerobic metabolisms. Our findings suggest new ways to approach the pacing for optimizing endurance performance.
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Affiliation(s)
- Jean-Renaud Pycke
- UMR8071—CNRS-Laboratoire de Mathématiques et Modélisation d’Evry (LaMME), University of Paris-Saclay (Evry), 91037 Evry, France
- Correspondence:
| | - Véronique Billat
- Department of STAPS, University of Paris-Saclay (Evry), 91037 Evry, France;
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21
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Volianitis S, Rasmussen P, Petersen NC, Secher NH. The Effect of Hyperoxia on Central and Peripheral Factors of Arm Flexor Muscles Fatigue Following Maximal Ergometer Rowing in Men. Front Physiol 2022; 13:829097. [PMID: 35185623 PMCID: PMC8850913 DOI: 10.3389/fphys.2022.829097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/11/2022] [Indexed: 11/16/2022] Open
Abstract
Purpose This study evaluates the effect of hyperoxia on cerebral oxygenation and neuromuscular fatigue mechanisms of the elbow flexor muscles following ergometer rowing. Methods In 11 competitive male rowers (age, 30 ± 4 years), we measured near-infrared spectroscopy determined frontal lobe oxygenation (ScO2) and transcranial Doppler ultrasound determined middle cerebral artery mean flow velocity (MCA Vmean) combined with maximal voluntary force (MVC), peak resting twitch force (Ptw) and cortical voluntary activation (VATMS) of the elbow flexor muscles using electrical motor point and magnetic motor cortex stimulation, respectively, before, during, and immediately after 2,000 m all-out effort on rowing ergometer with normoxia and hyperoxia (30% O2). Results Arterial hemoglobin O2 saturation was reduced to 92.5 ± 0.2% during exercise with normoxia but maintained at 98.9 ± 0.2% with hyperoxia. The MCA Vmean increased by 38% (p < 0.05) with hyperoxia, while only marginally increased with normoxia. Similarly, ScO2 was not affected with hyperoxia but decreased by 7.0 ± 4.8% from rest (p = 0.04) with normoxia. The MVC and Ptw were reduced (7 ± 3% and 31 ± 9%, respectively, p = 0.014), while VATMS was not affected by the rowing effort in normoxia. With hyperoxia, the deficit in MVC and Ptw was attenuated, while VATMS was unchanged. Conclusion These data indicate that even though hyperoxia restores frontal lobe oxygenation the resultant attenuation of arm muscle fatigue following maximal rowing is peripherally rather than centrally mediated.
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Affiliation(s)
- Stefanos Volianitis
- Department of Physical Education, College of Education, Qatar University, Doha, Qatar
| | - Peter Rasmussen
- Department of Anesthesiology, Rigshospitalet, Institute for Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Nicolas C Petersen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels H Secher
- Department of Anesthesiology, Rigshospitalet, Institute for Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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22
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Duke JW, Lewandowski AJ, Abman SH, Lovering AT. Physiological aspects of cardiopulmonary dysanapsis on exercise in adults born preterm. J Physiol 2022; 600:463-482. [PMID: 34961925 PMCID: PMC9036864 DOI: 10.1113/jp281848] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 12/03/2021] [Indexed: 02/03/2023] Open
Abstract
Progressive improvements in perinatal care and respiratory management of preterm infants have resulted in increased survival of newborns of extremely low gestational age over the past few decades. However, the incidence of bronchopulmonary dysplasia, the chronic lung disease after preterm birth, has not changed. Studies of the long-term follow-up of adults born preterm have shown persistent abnormalities of respiratory, cardiovascular and cardiopulmonary function, possibly leading to a lower exercise capacity. The underlying causes of these abnormalities are incompletely known, but we hypothesize that dysanapsis, i.e. discordant growth and development, in the respiratory and cardiovascular systems is a central structural feature that leads to a lower exercise capacity in young adults born preterm than those born at term. We discuss how the hypothesized system dysanapsis underscores the observed respiratory, cardiovascular and cardiopulmonary limitations. Specifically, adults born preterm have: (1) normal lung volumes but smaller airways, which causes expiratory airflow limitation and abnormal respiratory mechanics but without impacts on pulmonary gas exchange efficiency; (2) normal total cardiac size but smaller cardiac chambers; and (3) in some cases, evidence of pulmonary hypertension, particularly during exercise, suggesting a reduced pulmonary vascular capacity despite reduced cardiac output. We speculate that these underlying developmental abnormalities may accelerate the normal age-associated decline in exercise capacity, via an accelerated decline in respiratory, cardiovascular and cardiopulmonary function. Finally, we suggest areas of future research, especially the need for longitudinal and interventional studies from infancy into adulthood to better understand how preterm birth alters exercise capacity across the lifespan.
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Affiliation(s)
- Joseph W. Duke
- Northern Arizona University, Department of Biological Sciences, Flagstaff, AZ, USA
| | - Adam J. Lewandowski
- University of Oxford, Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford, UK
| | - Steven H. Abman
- University of Colorado Anschutz School of Medicine, Department of Pediatrics, Aurora, CO, USA,Pediatric Heart Lung Center, Children’s Hospital Colorado, Aurora, CO, USA
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23
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Marillier M, Gruet M, Bernard AC, Verges S, Neder JA. The Exercising Brain: An Overlooked Factor Limiting the Tolerance to Physical Exertion in Major Cardiorespiratory Diseases? Front Hum Neurosci 2022; 15:789053. [PMID: 35126072 PMCID: PMC8813863 DOI: 10.3389/fnhum.2021.789053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/28/2021] [Indexed: 12/18/2022] Open
Abstract
“Exercise starts and ends in the brain”: this was the title of a review article authored by Dr. Bengt Kayser back in 2003. In this piece of work, the author highlights that pioneer studies have primarily focused on the cardiorespiratory-muscle axis to set the human limits to whole-body exercise tolerance. In some circumstances, however, exercise cessation may not be solely attributable to these players: the central nervous system is thought to hold a relevant role as the ultimate site of exercise termination. In fact, there has been a growing interest relative to the “brain” response to exercise in chronic cardiorespiratory diseases, and its potential implication in limiting the tolerance to physical exertion in patients. To reach these overarching goals, non-invasive techniques, such as near-infrared spectroscopy and transcranial magnetic stimulation, have been successfully applied to get insights into the underlying mechanisms of exercise limitation in clinical populations. This review provides an up-to-date outline of the rationale for the “brain” as the organ limiting the tolerance to physical exertion in patients with cardiorespiratory diseases. We first outline some key methodological aspects of neuromuscular function and cerebral hemodynamics assessment in response to different exercise paradigms. We then review the most prominent studies, which explored the influence of major cardiorespiratory diseases on these outcomes. After a balanced summary of existing evidence, we finalize by detailing the rationale for investigating the “brain” contribution to exercise limitation in hitherto unexplored cardiorespiratory diseases, an endeavor that might lead to innovative lines of applied physiological research.
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Affiliation(s)
- Mathieu Marillier
- Laboratory of Clinical Exercise Physiology, Queen's University and Kingston General Hospital, Kingston, ON, Canada
- HP2 Laboratory, INSERM U1300, Grenoble Alpes University, Grenoble, France
| | - Mathieu Gruet
- IAPS Laboratory, University of Toulon, Toulon, France
| | - Anne-Catherine Bernard
- Laboratory of Clinical Exercise Physiology, Queen's University and Kingston General Hospital, Kingston, ON, Canada
- HP2 Laboratory, INSERM U1300, Grenoble Alpes University, Grenoble, France
| | - Samuel Verges
- HP2 Laboratory, INSERM U1300, Grenoble Alpes University, Grenoble, France
| | - J Alberto Neder
- Laboratory of Clinical Exercise Physiology, Queen's University and Kingston General Hospital, Kingston, ON, Canada
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24
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Płoszczyca K, Chalimoniuk M, Przybylska I, Czuba M. Effects of Short-Term Phosphate Loading on Aerobic Capacity under Acute Hypoxia in Cyclists: A Randomized, Placebo-Controlled, Crossover Study. Nutrients 2022; 14:236. [PMID: 35057416 PMCID: PMC8778537 DOI: 10.3390/nu14020236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/01/2022] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
The aim of this study was to evaluate the effects of sodium phosphate (SP) supplementation on aerobic capacity in hypoxia. Twenty-four trained male cyclists received SP (50 mg·kg-1 of FFM/day) or placebo for six days in a randomized, crossover study, with a three-week washout period between supplementation phases. Before and after each supplementation phase, the subjects performed an incremental exercise test to exhaustion in hypoxia (FiO2 = 16%). Additionally, the levels of 2,3-diphosphoglycerate (2,3-DPG), hypoxia-inducible factor 1 alpha (HIF-1α), inorganic phosphate (Pi), calcium (Ca), parathyroid hormone (PTH) and acid-base balance were determined. The results showed that phosphate loading significantly increased the Pi level by 9.0%, whereas 2,3-DPG levels, hemoglobin oxygen affinity, buffering capacity and myocardial efficiency remained unchanged. The aerobic capacity in hypoxia was not improved following SP. Additionally, our data revealed high inter-individual variability in response to SP. Therefore, the participants were grouped as Responders and Non-Responders. In the Responders, a significant increase in aerobic performance in the range of 3-5% was observed. In conclusion, SP supplementation is not an ergogenic aid for aerobic capacity in hypoxia. However, in certain individuals, some benefits can be expected, but mainly in athletes with less training-induced central and/or peripheral adaptation.
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Affiliation(s)
- Kamila Płoszczyca
- Department of Kinesiology, Institute of Sport, 01-982 Warsaw, Poland
| | - Małgorzata Chalimoniuk
- Department of Physiotherapy, Faculty of Physical Education and Health in Biala Podlaska, Jozef Pilsudski University of Physical Education in Warsaw, 21-500 Biala Podlaska, Poland
| | - Iwona Przybylska
- Department of Physiotherapy, Faculty of Physical Education and Health in Biala Podlaska, Jozef Pilsudski University of Physical Education in Warsaw, 21-500 Biala Podlaska, Poland
| | - Miłosz Czuba
- Department of Kinesiology, Institute of Sport, 01-982 Warsaw, Poland
- Faculty of Rehabilitation, Jozef Pilsudski University of Physical Education in Warsaw, 00-968 Warsaw, Poland
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25
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Cardoso AM, Silvério MNO, de Oliveira Maciel SFV. Purinergic signaling as a new mechanism underlying physical exercise benefits: a narrative review. Purinergic Signal 2021; 17:649-679. [PMID: 34590239 PMCID: PMC8677870 DOI: 10.1007/s11302-021-09816-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/21/2021] [Indexed: 11/27/2022] Open
Abstract
In the last years, it has become evident that both acute and chronic physical exercise trigger responses/adaptations in the purinergic signaling and these adaptations can be considered one important mechanism related to the exercise benefits for health improvement. Purinergic system is composed of enzymes (ectonucleotidases), receptors (P1 and P2 families), and molecules (ATP, ADP, adenosine) that are able to activate these receptors. These components are widely distributed in almost all cell types, and they respond/act in a specific manner depending on the exercise types and/or intensities as well as the cell type (organ/tissue analyzed). For example, while acute intense exercise can be associated with tissue damage, inflammation, and platelet aggregation, chronic exercise exerts anti-inflammatory and anti-aggregant effects, promoting health and/or treating diseases. All of these effects are dependent on the purinergic signaling. Thus, this review was designed to cover the aspects related to the relationship between physical exercise and purinergic signaling, with emphasis on the modulation of ectonucleotidases and receptors. Here, we discuss the impact of different exercise protocols as well as the differences between acute and chronic effects of exercise on the extracellular signaling exerted by purinergic system components. We also reinforce the concept that purinergic signaling must be understood/considered as a mechanism by which exercise exerts its effects.
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Affiliation(s)
- Andréia Machado Cardoso
- Graduate Program in Biomedical Sciences and Medicine Course, Federal University of Fronteira Sul - UFFS, Campus Chapecó, Rodovia SC 484 - Km 02, Fronteira Sul, 89815-899, Brazil.
- Graduate Program in Physical Education, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Mauro Nicollas Oliveira Silvério
- Medicine Course, Federal University of Fronteira Sul - UFFS, Campus Chapecó, Rodovia SC 484 - Km 02, Fronteira Sul, 89815-899, Brazil
| | - Sarah Franco Vieira de Oliveira Maciel
- Graduate Program in Biomedical Sciences and Medicine Course, Federal University of Fronteira Sul - UFFS, Campus Chapecó, Rodovia SC 484 - Km 02, Fronteira Sul, 89815-899, Brazil
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26
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Da Silva KJ, Silva LC, Felippe LC, Silva-Cavalcante MD, Franco-Alvarenga PE, Learsi S, Ataide-Silva T, Bertuzzi R, Lima-Silva AE, Ferreira GA. Airflow restriction mask induces greater central fatigue after a non-exhaustive high-intensity interval exercise. Scand J Med Sci Sports 2021; 32:487-497. [PMID: 34787931 DOI: 10.1111/sms.14099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/23/2021] [Accepted: 11/12/2021] [Indexed: 11/26/2022]
Abstract
The airflow restriction mask (ARM) is a practical and inexpensive device for respiratory muscle training. Wearing an ARM has recently been combined with high-intensity interval exercise (HIIE), but its effect on neuromuscular fatigue is unknown. The present study investigated the effects of ARM wearing on neuromuscular fatigue after an HIIE session. Fourteen healthy men performed two HIIE sessions (4x4min at 90% HRmax, 3min recovery at 70% HRmax) with or without an ARM. Neuromuscular fatigue was quantified via pre- to post-HIIE changes in maximal voluntary contraction (MVC), voluntary activation (VA, central fatigue), and potentialized evoked twitch force at 100, 10, and 1 Hz (peripheral fatigue). Blood pH and lactate were measured before and after the HIIE session, while HR, SpO2 , dyspnea, physical sensation of effort (P-RPE), and Task Effort and Awareness (TEA) were recorded every bout. The exercise-induced decrease in MVC was higher (p<0.05) in the ARM (-28±12%) than in the control condition (-20±11%). The VA decreased (p<0.05) in the ARM (-11±9%) but not in the control condition (-4±5%, p>0.05). Pre- to post-HIIE declines in evoked twitch at 100, 10, and 1 Hz were similar (p>0.05) between ARM and control conditions (ARM: -18±10, -43±11 and -38±12%; Control: -18±14, -43±12 and -37±17%). When compared with the control, the HIIE bout wearing ARM was marked by higher heart rate, plasma lactate concentration, dyspnea, P-RPE and TEA, as well as lower SpO2 and blood pH. In conclusion, ARM increases perceptual and physiological stress during a HIIE, which may lead to a greater post-exercise central fatigue.
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Affiliation(s)
- Kleber J Da Silva
- Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology Parana, Curitiba, Parana, Brazil
| | - Lucas C Silva
- Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil
| | - Leandro C Felippe
- Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology Parana, Curitiba, Parana, Brazil
| | - Marcos D Silva-Cavalcante
- Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology Parana, Curitiba, Parana, Brazil
| | - Paulo E Franco-Alvarenga
- Exercise Psychophysiology Research Group, University of Sao Paulo, Sao Paulo, Sao Paulo, Brazil.,Estacio de Sa University, UNESA, Resende, Rio de Janeiro, Brazil
| | - Sara Learsi
- Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil
| | - Thays Ataide-Silva
- Department of nutrition, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | - Romulo Bertuzzi
- Endurance Performance Research Group, School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Sao Paulo, Brazil
| | - Adriano E Lima-Silva
- Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology Parana, Curitiba, Parana, Brazil
| | - Guilherme A Ferreira
- Academic Center of Vitoria, Federal University of Pernambuco, Vitoria de Santo Antao, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology Parana, Curitiba, Parana, Brazil
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27
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McKeown DJ, McNeil CJ, Brotherton EJ, Simmonds MJ, Kavanagh JJ. Severe acute hypoxia impairs recovery of voluntary muscle activation after sustained submaximal elbow flexion. J Physiol 2021; 599:5379-5395. [PMID: 34761807 DOI: 10.1113/jp281897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 11/04/2021] [Indexed: 11/08/2022] Open
Abstract
The purpose of this study was to determine how severe acute hypoxia alters neural mechanisms during, and following, a sustained fatiguing contraction. Fifteen participants (25 ± 3.2 years, six female) were exposed to a sham condition and a hypoxia condition where they performed a 10 min elbow flexor contraction at 20% of maximal torque. For hypoxia, peripheral blood oxygen saturation ( S p O 2 ) was titrated to 80% over a 15 min period and maintained for 2 h. Maximal voluntary contraction torque, EMG root mean square, voluntary activation, rating of perceived muscle fatigue, and corticospinal excitability (motor-evoked potential) and inhibition (silent period duration) were then assessed before, during and for 6 min after the fatiguing contraction. No hypoxia-related effects were identified for neuromuscular variables during the fatigue task. However, for recovery, voluntary activation assessed by motor point stimulation of biceps brachii was lower for hypoxia than sham at 4 min (sham: 89% ± 7%; hypoxia: 80% ± 12%; P = 0.023) and 6 min (sham: 90% ± 7%; hypoxia: 78% ± 11%; P = 0.040). Similarly, voluntary activation (P = 0.01) and motor-evoked potential area (P = 0.002) in response to transcranial magnetic stimulation of the motor cortex were 10% and 11% lower during recovery for hypoxia compared to sham, respectively. Although an S p O 2 of 80% did not affect neural activity during the fatiguing task, motor cortical output and corticospinal excitability were reduced during recovery in the hypoxic environment. This was probably due to hypoxia-related mechanisms involving supraspinal motor circuits. KEY POINTS: Acute hypoxia has been shown to impair voluntary activation of muscle and alter the excitability of the corticospinal motor pathway during exercise. However, little is known about how hypoxia alters the recovery of the motor system after performing fatiguing exercise. Here we assessed hypoxia-related responses of motor pathways both during active contractions and during recovery from active contractions, with transcranial magnetic stimulation and motor point stimulation of the biceps brachii. Fatiguing exercise caused reductions in voluntary activation, which was exacerbated during recovery from a 10 min sustained elbow flexion in a hypoxic environment. These results suggest that reductions in blood oxygen concentration impair the ability of motor pathways in the CNS to recover from fatiguing exercise, which is probably due to hypoxia-induced mechanisms that reduce output from the motor cortex.
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Affiliation(s)
- Daniel J McKeown
- Neural Control of Movement Laboratory, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Chris J McNeil
- Integrated Neuromuscular Physiology Laboratory, Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Emily J Brotherton
- Neural Control of Movement Laboratory, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Michael J Simmonds
- Biorheology Research Laboratory, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Justin J Kavanagh
- Neural Control of Movement Laboratory, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
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28
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Möller F, Jacobi E, Hoffmann U, Muth T, Schipke JD. Oxygen-enriched Air Decreases Ventilation during High-intensity Fin-swimming Underwater. Int J Sports Med 2021; 43:230-236. [PMID: 34399427 PMCID: PMC8885326 DOI: 10.1055/a-1554-5093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Oxygen-enriched air is commonly used in the sport of SCUBA-diving and might affect ventilation and heart rate, but little work exists for applied diving settings. We hypothesized that ventilation is decreased especially during strenuous underwater fin-swimming when using oxygen-enriched air as breathing gas. Ten physically-fit divers (age: 25±4; 5 females; 67±113 open-water dives) performed incremental underwater fin-swimming until exhaustion at 4 m water depth with either normal air or oxygen-enriched air (40% O
2
) in a double-blind, randomized within-subject design. Heart rate and ventilation were measured throughout the dive and maximum whole blood lactate samples were determined post-exercise. ANOVAs showed a significant effect for the factor breathing gas (F(1, 9)=7.52; P=0.023; η
2p
=0.455), with a lower ventilation for oxygen-enriched air during fin-swimming velocities of 0.6 m·s
−1
(P=0.032) and 0.8 m·s
−1
(P=0.037). Heart rate, lactate, and time to exhaustion showed no significant differences. These findings indicate decreased ventilation by an elevated oxygen fraction in the breathing gas when fin-swimming in shallow-water submersion with high velocity (>0.5 m·s
−1
). Applications are within involuntary underwater exercise or rescue scenarios for all dives with limited gas supply.
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Affiliation(s)
- Fabian Möller
- Department of Exercise Physiology, German Sport University Cologne, Cologne, Germany
| | - Elena Jacobi
- Department of Exercise Physiology, German Sport University Cologne, Cologne, Germany
| | - Uwe Hoffmann
- Department of Exercise Physiology, German Sport University Cologne, Cologne, Germany
| | - Thomas Muth
- Occupational, Social, Environmental Medicine, Heinrich-Heine-Universitat Dusseldorf, Dusseldorf, Germany
| | - Jochen D Schipke
- Research Group Experimenal Surgery, University Hospital Düsseldorf, Dusseldorf, Germany
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29
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Niespodziński B, Mieszkowski J, Kochanowicz M, Kochanowicz A, Antosiewicz J. Effect of 10 consecutive days of remote ischemic preconditioning on local neuromuscular performance. J Electromyogr Kinesiol 2021; 60:102584. [PMID: 34388409 DOI: 10.1016/j.jelekin.2021.102584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/23/2021] [Accepted: 08/01/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Most studies focus on the effects of a single remote ischemic preconditioning (RIPC) session on performance. However, the training-like effect of repeat RIPC sessions performed on consecutive days could potentially be even more beneficial to neuromuscular performance than a single RIPC session. Therefore, aim of the study was to assess the impact of 10 days of RIPC on local neuromuscular performance. METHODS Thirty-seven male participants performed 10 days of either RIPC or sham-controlled condition. Before and after procedure, the maximal voluntary contraction and muscle fatigue were assessed by dynamometry and surface electromyography (EMG) of the isometric extension of the knee joint. The following neuromuscular outcomes were investigated: peak torque (PKTQ); rate of force development (RTD); time to failure; and the slope of median frequency of power spectrum (MDF) and EMG amplitude. RESULTS After RIPC, while there was no change in PKTQ and time to failure, the late RTD and MDF slope were significantly affected. The RTD at 0-100 and 0-200 ms showed 24 and 16% increase, respectively, while the MDF slope showed 24% decrease in rectus femoris. CONCLUSIONS 10 days of RIPC induced neuromuscular performance changes in the quadriceps muscle. Even though there were no changes in task to failure performance, RIPC showed EMG changes limited to rectus femoris and increased late RTD in MVC task.
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Affiliation(s)
- Bartłomiej Niespodziński
- Department of Human Biology, Institute of Physical Education, Kazimierz Wielki University, Bydgoszcz, Poland.
| | - Jan Mieszkowski
- Department of Gymnastics and Dance, Gdansk University of Physical Education and Sport, Gdańsk, Poland
| | - Magdalena Kochanowicz
- Department of Physiotherapy, The Faculty of Health Sciences with the Institute of Maritime and Tropical Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Andrzej Kochanowicz
- Department of Gymnastics and Dance, Gdansk University of Physical Education and Sport, Gdańsk, Poland
| | - Jędrzej Antosiewicz
- Department of Bioenergetics and Physiology of Exercise, Medical University of Gdańsk, Gdańsk, Poland
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30
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Øvretveit K, Laginestra FG. Mechanisms and Trainability of Peripheral Fatigue in Grappling. Strength Cond J 2021. [DOI: 10.1519/ssc.0000000000000594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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31
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Müller J, Lichtblau M, Saxer S, Calendo LR, Carta AF, Schneider SR, Berlier C, Furian M, Bloch KE, Schwarz EI, Ulrich S. Effect of Breathing Oxygen-Enriched Air on Exercise Performance in Patients With Pulmonary Hypertension Due to Heart Failure With Preserved Ejection Fraction: A Randomized, Placebo-Controlled, Crossover Trial. Front Med (Lausanne) 2021; 8:692029. [PMID: 34395475 PMCID: PMC8357069 DOI: 10.3389/fmed.2021.692029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/24/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: To evaluate the effects of breathing oxygen-enriched air (oxygen) on exercise performance in patients with pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF). Methods: Ten patients with PH-HFpEF (five women, age 60 ± 9 y, mPAP 37 ± 14 mmHg, PAWP 18 ± 2 mmHg, PVR 3 ± 3 WU, resting SpO2 98 ± 2%) performed two-cycle incremental exercise tests (IET) and two constant-work-rate exercise test (CWRET) at 75% maximal work-rate (Wmax), each with ambient air (FiO2 0.21) and oxygen (FiO2 0.5) in a randomized, single-blinded, cross-over design. The main outcomes were the change in Wmax (IET) and cycling time (CWRET) with oxygen vs. air. Blood gases at rest and end-exercise, dyspnea by Borg CR10 score at end-exercise; continuous SpO2, minute ventilation (V'E), carbon dioxide output (V'CO2), and cerebral and quadricep muscle tissue oxygenation (CTO and QMTO) were measured. Results: With oxygen vs. air, Wmax (IET) increased from 94 ± 36 to 99 ± 36 W, mean difference (95% CI) 5.4 (0.9–9.8) W, p = 0.025, and cycling time (CWRET) from 532 ± 203 to 680 ± 76 s, +148 (31.8–264) s, p = 0.018. At end-exercise with oxygen, Borg dyspnea score and V'E/V'CO2 were lower, whereas PaO2 and end-tidal PaCO2 were higher. Other parameters were unchanged. Conclusion: Patients with PH-HFpEF not revealing resting hypoxemia significantly improved their exercise performance while breathing oxygen-enriched air along with less subjective dyspnea sensation, a better blood oxygenation, and an enhanced ventilatory efficiency. Future studies should investigate whether prolonged training with supplemental oxygen would increase the training effect and, potentially, daily activity for PH-HFpEF patients. Clinical Trial Registration: [clinicaltrials.gov], identifier [NCT04157660].
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Affiliation(s)
- Julian Müller
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Mona Lichtblau
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Stéphanie Saxer
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Luigi-Riccardo Calendo
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Arcangelo F Carta
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Simon R Schneider
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Charlotte Berlier
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Michael Furian
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Konrad E Bloch
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland.,Centre for Integrative Human Physiology, University of Zürich, Zürich, Switzerland
| | - Esther I Schwarz
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland
| | - Silvia Ulrich
- Pulmonary Clinic, University Hospital Zürich, Zürich, Switzerland.,Faculty of Medicine, University of Zürich, Zürich, Switzerland.,Centre for Integrative Human Physiology, University of Zürich, Zürich, Switzerland
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32
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Fietsam AC, Deters JR, Workman CD, Rudroff T. Personal Protective Equipment Alters Leg Muscle Fatigability Independent of Transcranial Direct Current Stimulation: A Comparison with Pre-COVID-19 Pandemic Results. Brain Sci 2021; 11:brainsci11080962. [PMID: 34439581 PMCID: PMC8392507 DOI: 10.3390/brainsci11080962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/02/2021] [Accepted: 07/19/2021] [Indexed: 01/12/2023] Open
Abstract
In response to the COVID-19 pandemic, the use of personal protective equipment (PPE; e.g., face mask) has increased. Mandating subjects to wear PPE during vigorous exercise might affect the fatigue outcomes of transcranial direct current stimulation (tDCS) studies. The purpose of this study was to investigate whether the use of PPE affected the performance of a tDCS-influenced fatigue task in healthy adults. A total of 16 young and healthy subjects were recruited and wore PPE during an isokinetic fatigue task in conjunction with sham, 2 mA, and 4 mA tDCS conditions. Subjects were matched to subjects who did not wear PPE during our previous pre-pandemic study in which right knee extensor fatigability increased under these same conditions. The results show that right knee extensor fatigability, derived from torque and work (FI-T and FI-W, respectively), was higher in the PPE study compared to the No PPE study in the sham condition. Additionally, there were no differences in knee extensor fatigability or muscle activity between sham, 2 mA, and 4 mA tDCS in the present study, which contrasts with our previous results. Thus, PPE worn by subjects and researchers might have a detrimental effect on fatigue outcomes in tDCS studies irrespective of the stimulation intervention.
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Affiliation(s)
- Alexandra C. Fietsam
- Department of Health and Human Physiology, University of Iowa, Iowa City, IA 52242, USA; (A.C.F.); (J.R.D.); (C.D.W.)
| | - Justin R. Deters
- Department of Health and Human Physiology, University of Iowa, Iowa City, IA 52242, USA; (A.C.F.); (J.R.D.); (C.D.W.)
| | - Craig D. Workman
- Department of Health and Human Physiology, University of Iowa, Iowa City, IA 52242, USA; (A.C.F.); (J.R.D.); (C.D.W.)
| | - Thorsten Rudroff
- Department of Health and Human Physiology, University of Iowa, Iowa City, IA 52242, USA; (A.C.F.); (J.R.D.); (C.D.W.)
- Department of Neurology, University of Iowa Health Clinics, Iowa City, IA 52242, USA
- Correspondence: ; Tel.: +1-319-467-0363
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33
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Kristiansen M, Thomsen MJ, Nørgaard J, Aaes J, Knudsen D, Voigt M. Anodal transcranial direct current stimulation increases corticospinal excitability, while performance is unchanged. PLoS One 2021; 16:e0254888. [PMID: 34270614 PMCID: PMC8284656 DOI: 10.1371/journal.pone.0254888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 07/07/2021] [Indexed: 11/26/2022] Open
Abstract
Anodal transcranial direct current stimulation (a-tDCS) has been shown to improve bicycle time to fatigue (TTF) tasks at 70–80% of VO2max and downregulate rate of perceived exertion (RPE). This study aimed to investigate the effect of a-tDCS on a RPE-clamp test, a 250-kJ time trial (TT) and motor evoked potentials (MEP). Twenty participants volunteered for three trials; control, sham stimulation and a-tDCS. Transcranial magnetic stimulation was used to determine the corticospinal excitability for 12 participants pre and post sham stimulation and a-tDCS. The a-tDCS protocol consisted of 13 minutes of stimulation (2 mA) with the anode placed above the Cz. The RPE-clamp test consisted of 5 minutes ergometer bicycling at an RPE of 13 on the Borg scale, and the TT consisted of a 250 kJ (∼10 km) long bicycle ergometer test. During each test, power output, heart rate and oxygen consumption was measured, while RPE was evaluated. MEPs increased significantly by 36% (±36%) post a-tDCS, with 8.8% (±31%) post sham stimulation (p = 0.037). No significant changes were found for any parameter at the RPE-clamp or TT. The lack of improvement may be due to RPE being more controlled by afferent feedback during TT tests than during TTF tests. Based on the results of the present study, it is concluded that a-tDCS applied over Cz, does not enhance self-paced cycling performance.
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Affiliation(s)
- Mathias Kristiansen
- Department of Health Science and Technology, Sport Sciences–Performance and Technology, Aalborg University, Aalborg, Denmark
- * E-mail:
| | - Mikkel Jacobi Thomsen
- Department of Health Science and Technology, Sport Sciences–Performance and Technology, Aalborg University, Aalborg, Denmark
| | - Jens Nørgaard
- Department of Health Science and Technology, Sport Sciences–Performance and Technology, Aalborg University, Aalborg, Denmark
| | - Jon Aaes
- Department of Health Science and Technology, Sport Sciences–Performance and Technology, Aalborg University, Aalborg, Denmark
| | - Dennis Knudsen
- Department of Health Science and Technology, Sport Sciences–Performance and Technology, Aalborg University, Aalborg, Denmark
| | - Michael Voigt
- Department of Health Science and Technology, Sport Sciences–Performance and Technology, Aalborg University, Aalborg, Denmark
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Drouin PJ, Walsh JJ, Swart J, Day TA, Tschakovsky ME. Perceived mental strain dissociates from perceived physical strain during relative intensity submaximal exercise on ascent from low to high altitude. Physiol Rep 2021; 9:e14934. [PMID: 34231339 PMCID: PMC8261485 DOI: 10.14814/phy2.14934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 05/26/2021] [Indexed: 11/24/2022] Open
Abstract
Perceived fatigability, which has perception of physical strain and of mental strain as its components, can impact exercise tolerance. Upon ascent to high altitude, low landers experience reduced exercise capacity and reduced tolerance for a given absolute submaximal work rate. It is established that perceived physical strain tracks with relative exercise intensity. However, it is not known how altitude ascent affects perceived mental strain relative to perceived physical strain. We tested the hypothesis that when exercising at the same relative exercise intensity perceived physical strain will remain unchanged whereas perceived mental strain will decrease on ascent from low to high altitude in the Everest region in Nepal. Twelve hours after arriving at each of three elevations; 1400 m, 3440 m, and 4240 m, 12 untrained participants used the task effort awareness (TEA) and physical-rating of perceived exertion (P-RPE) scales to report perceived mental and physical strain during a 20 min walking test at a self-monitored heart rate reserve (HRR) range of 40-60% (Polar HR Monitor). TEA and P-RPE were recorded twice during exercise (5-7 min and 14-16 min). Neither P-RPE (1400 m: 11.1 ± 1.8, 3440 m: 10.7 ± 1.2, 4240 m: 11.5 ± 1.5) nor %HRR (1400 m: 55.25 ± 7.34, 3440 m: 51.70 ± 6.70, 4240 m: 50.17 ± 4.02) changed as altitude increased. TEA decreased at 4240 m (2.05 ± 0.71) compared to 1400 m (3.44 ± 0.84)--this change was not correlated with any change in %HRR nor was it due to a change in core affect. These findings support our hypothesis and demonstrate the independence of perceived physical and perceived mental strain components of perceived fatigability. Implications for exercise tolerance remain to be determined.
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Affiliation(s)
- Patrick J. Drouin
- Human Vascular Control LaboratorySchool of Kinesiology and Health StudiesQueen's UniversityKingstonONCanada
| | - Jeremy J. Walsh
- Human Vascular Control LaboratorySchool of Kinesiology and Health StudiesQueen's UniversityKingstonONCanada
- Exercise Metabolism and Inflammation LaboratoryUniversity of British Columbia OkanaganKelownaBCCanada
- Department of KinesiologyMcMaster UniversityHamiltonONCanada
| | - Jeroen Swart
- UCT/MRC Research Unit for Exercise Science and Sports MedicineDepartment of Human BiologySports Science Institute of South AfricaUniversity of Cape TownCape TownSouth Africa
| | - Trevor A. Day
- Department of BiologyFaculty of Science and TechnologyMount Royal UniversityCalgaryABCanada
| | - Michael E. Tschakovsky
- Human Vascular Control LaboratorySchool of Kinesiology and Health StudiesQueen's UniversityKingstonONCanada
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Płoszczyca K, Czuba M, Chalimoniuk M, Gajda R, Baranowski M. Red Blood Cell 2,3-Diphosphoglycerate Decreases in Response to a 30 km Time Trial Under Hypoxia in Cyclists. Front Physiol 2021; 12:670977. [PMID: 34211402 PMCID: PMC8239298 DOI: 10.3389/fphys.2021.670977] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/11/2021] [Indexed: 11/14/2022] Open
Abstract
Red blood cell 2,3-diphosphoglycerate (2,3-DPG) is one of the factors of rightward-shifted oxygen dissociation curves and decrease of Hb-O2 affinity. The reduction of Hb-O2 affinity is beneficial to O2 unloading at the tissue level. In the current literature, there are no studies about the changes in 2,3-DPG level following acute exercise in moderate hypoxia in athletes. For this reason, the aim of this study was to analyze the effect of prolonged intense exercise under normoxic and hypoxic conditions on 2,3-DPG level in cyclists. Fourteen male trained cyclists performed a simulation of a 30 km time trial (TT) in normoxia and normobaric hypoxia (FiO2 = 16.5%, ~2,000 m). During the TT, the following variables were measured: power, blood oxygen saturation (SpO2), and heart rate (HR). Before and immediately after exercise, the blood level of 2,3-DPG and acid–base equilibrium were determined. The results showed that the mean SpO2 during TT in hypoxia was 8% lower than in normoxia. The reduction of SpO2 in hypoxia resulted in a decrease of average power by 9.6% (p < 0.001) and an increase in the 30 km TT completion time by 3.8% (p < 0.01) compared to normoxia. The exercise in hypoxia caused a significant (p < 0.001) decrease in 2,3-DPG level by 17.6%. After exercise in normoxia, a downward trend of 2,3-DPG level was also observed, but this effect was not statistically significant. The analysis also revealed that changes of acid–base balance were significantly larger (p < 0.05) after exercise in hypoxia than in normoxia. In conclusion, intense exercise in hypoxic conditions leads to a decrease in 2,3-DPG concentration, primarily due to exercise-induced acidosis.
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Affiliation(s)
- Kamila Płoszczyca
- Department of Kinesiology, Institute of Sport - National Research Institute, Warsaw, Poland
| | - Miłosz Czuba
- Department of Kinesiology, Institute of Sport - National Research Institute, Warsaw, Poland
| | - Małgorzata Chalimoniuk
- Department of Physical Education and Health in Biala Podlaska, Józef Piłsudski University of Physical Education in Warsaw, Biala Podlaska, Poland
| | - Robert Gajda
- Center for Sports Cardiology, Gajda-Med Medical Center in Pułtusk, Pułtusk, Poland
| | - Marcin Baranowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
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Dotan R, Woods S, Contessa P. On the reliability and validity of central fatigue determination. Eur J Appl Physiol 2021; 121:2393-2411. [PMID: 33966110 DOI: 10.1007/s00421-021-04700-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/24/2021] [Indexed: 11/30/2022]
Abstract
Physical performance fatigue can be ascribed to both peripheral and central components. Central fatigue, however, is an elusive entity, consisting of cognitive/sensory component and presumably also a neuro-physiological component that are difficult to tease apart and assess independently of each other. The most widely accepted method for the assessment of central fatigue is based on the premise that decreasing volitional muscle activation (VA), as determined by the interpolated twitch technique (ITT) in fatiguing muscles, reflects increasing central fatigue. Suffering its own shortcomings, the validity of VA determination under fatigued conditions has never been proven and is only assumed. This review presents evidence that questions ITT's reliability and validity in reflecting VA in the fatiguing muscle and, consequently, VA's validity for central fatigue assessment. Specifically highlighted is the paradox of children and endurance athletes, who share striking endurance characteristics, being claimed as more centrally fatigable than untrained adults. Further research and new directions are needed for confirming and quantifying central fatigue and teasing apart its psychologic and neuromotor components.
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Affiliation(s)
- Raffy Dotan
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada.
| | - Stacey Woods
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada
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Bailey CA, Yoon S, Côté JN. Relative variability in muscle activation amplitude, muscle oxygenation, and muscle thickness: Changes with dynamic low-load elbow flexion fatigue and relationships in young and older females. J Electromyogr Kinesiol 2021; 59:102553. [PMID: 34010758 DOI: 10.1016/j.jelekin.2021.102553] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 10/21/2022] Open
Abstract
In repetitive upper limb activities, variability of muscle activity (a feature of motor variability) is linked to upper limb fatigability. Prior studies suggest that the variability response may change with age and could be related to the oxygen saturation of hemoglobin within the muscle. We determined, in female adults, how age affects adjustments in movement-to-movement variability of electromyograph (EMG) amplitude (RMS), oxygenation, and thickness with fatigue, and explored how these responses were related. Fifteen young (23.3 ± 3.1 years) and ten older (62.8 ± 6.9 years) females completed repeated trials of low-load, isokinetic, concentric/eccentric elbow flexion until maximal torque ≤ 70% of baseline. Movement-to-movement variability of EMG RMS in concentric phases of movement was quantified by the coefficient of variation (EMG CV), and muscle oxygenation and thickness (MTH) were quantified using near-infrared spectroscopy, and B-mode ultrasonography. Age*Time and Spearman ρ analyses were conducted. Age did not affect fatigability or Time-related changes in muscular measures (p > 0.05). Biceps brachii and brachialis EMG CV decreased, biceps brachii HbO2 decreased and did not fully recover, and biceps brachii and brachialis MTH increased. Higher initial brachialis EMG CV was related to less blunted oxygenation in young females (p = 0.021). Oxygenation responses were related to altered anterior deltoid EMG CV in young females but altered biceps brachii and brachialis EMG CV in older females. Age was not associated with changes in EMG CV, oxygenation, or thickness at similar performance fatigability in the concentric/eccentric elbow flexion task studied. Adjustments in biceps brachii oxygenation were linked to changes in EMG CV more local to the site of fatigue with older age.
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Affiliation(s)
- Christopher A Bailey
- Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, Quebec H2W1S4, Canada.
| | - SangHoon Yoon
- Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, Quebec H2W1S4, Canada
| | - Julie N Côté
- Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, Quebec H2W1S4, Canada
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González-Hernández JM, García-Ramos A, Colomer-Poveda D, Tvarijonaviciute A, Cerón J, Jiménez-Reyes P, Márquez G. Resistance Training to Failure vs. Not to Failure: Acute and Delayed Markers of Mechanical, Neuromuscular, and Biochemical Fatigue. J Strength Cond Res 2021; 35:886-893. [PMID: 33306589 DOI: 10.1519/jsc.0000000000003921] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT González-Hernández, JM, García-Ramos, A, Colomer-Poveda, D, Tvarijonaviciute, A, Cerón, J, Jiménez-Reyes, P, and Márquez, G. Resistance training to failure vs. not to failure: acute and delayed markers of mechanical, neuromuscular, and biochemical fatigue. J Strength Cond Res 35(4): 886-893, 2021-This study aimed to compare acute and delayed markers of mechanical, neuromuscular, and biochemical fatigue between resistance training sessions leading to or not to failure. Twelve resistance-trained men completed 2 sessions that consisted of 6 sets of the full-squat exercise performed against the 10 repetitions maximum load. In a randomized order, in one session the sets were performed to failure and in the other session the sets were not performed to failure (5 repetitions per set). Mechanical fatigue was quantified through the recording of the mean velocity during all repetitions. The neuromuscular function of the knee extensors was assessed through a maximal voluntary contraction and the twitch interpolation technique before training, immediately after each set, and 1, 24, and 48 hours post-training. Serum creatine kinase (CK) and aspartate aminotransferase (AST) were measured before training and 1, 24, and 48 hours post-training to infer muscle damage. Alpha was set at a level of 0.05. A higher velocity loss between sets was observed during the failure protocol (-21.7%) compared with the nonfailure protocol (-3.5%). The markers of peripheral fatigue were generally higher and long lasting for the failure protocol. However, the central fatigue assessed by the voluntary activation was comparable for both protocols and remained depressed up to 48 hours post-training. The concentrations of CK and AST were higher after the failure protocol revealing higher muscle damage compared with the nonfailure protocol. These results support the nonfailure protocol to reduce peripheral fatigue and muscle damage, whereas the central fatigue does not seem to be affected by the set configuration.
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Affiliation(s)
- Jorge M González-Hernández
- Faculty of Health Science, European University of Canarias, Tenerife, Spain.,Department of Physical Education and Sport, Faculty of Sport Sciences, Catholic University of Murcia (UCAM), Murcia, Spain
| | - Amador García-Ramos
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain.,Department of Sports Sciences and Physical Conditioning, Faculty of Education, Catholic University of the Most Holy Concepcion, Concepción, Chile
| | - David Colomer-Poveda
- Department of Physical Education and Sport, Faculty of Sport Sciences, Catholic University of Murcia (UCAM), Murcia, Spain
| | - Asta Tvarijonaviciute
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Regional Campus of International Excellence "Campus Mare Nostrum," University of Murcia, Murcia, Spain
| | - José Cerón
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Regional Campus of International Excellence "Campus Mare Nostrum," University of Murcia, Murcia, Spain
| | | | - Gonzalo Márquez
- Department of Physical Education and Sport, Faculty of Sport Sciences, Catholic University of Murcia (UCAM), Murcia, Spain.,Department of Physical Education, Faculty of Sport Sciences and Physical Education, University of A Coruña, A Coruña, Spain
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Azevedo RDA, Cruz R, Hasegawa JS, Gáspari AF, Chacon-Mikahil MPT, Silva-Cavalcante MD, Coelho DB, Lima-Silva AE, Bertuzzi R. Effects of induced local ischemia during a 4-km cycling time trial on neuromuscular fatigue development. Am J Physiol Regul Integr Comp Physiol 2021; 320:R812-R823. [PMID: 33787348 DOI: 10.1152/ajpregu.00312.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study analyzed the effects of local ischemia during endurance exercise on neuromuscular fatigue (NMF). Nine cyclists performed, in a counterbalanced order, two separate 4-km cycling time trials (TT) with (ISCH) or without (CONTR) induced local ischemia. NMF was characterized by using isometric maximal voluntary contractions (IMVC), whereas central [voluntary activation (VA)] and peripheral fatigue [peak torque of potentiated twitch (TwPt)] of knee extensors were evaluated using electrically evoked contractions performed before (PRE) and 1 min after (POST) the TT. Electromyographic activity (EMG), power output (PO), oxygen uptake (V̇o2), and rating of perceived exertion (RPE) were also recorded. The decrease in IMVC (-15 ± 9% vs. -10 ± 8%, P = 0.66), VA (-4 ± 3% vs. -3 ± 3%, P = 0.46), and TwPt (-16 ± 7% vs. -19 ± 14%, P = 0.67) was similar in ISCH and CONTR. Endurance performance was drastically reduced in ISCH condition (512 ± 29 s) compared with CONTR (386 ± 17 s) (P < 0.001), which was accompanied by lower EMG, PO, and V̇o2 responses (all P < 0.05). RPE was greater in ISCH compared with CONTR (P < 0.05), but the rate of change was similar throughout the TT (8.19 ± 2.59 vs. 7.81 ± 2.01 RPE.% of total time-1, P > 0.05). These results indicate that similar end-exercise NMF levels were accompanied by impaired endurance performance in ISCH compared with CONTR. These novel findings suggest that the local reduced oxygen availability affected the afferent feedback signals to the central nervous system, ultimately increasing perceived effort and reducing muscle activity and exercise intensity to avoid surpassing a sensory tolerance limit before the finish line.
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Affiliation(s)
- Rafael de Almeida Azevedo
- Endurance Performance Research Group, School of Physical Education and Sport , University of São Paulo, São Paulo, Brazil
| | - Ramon Cruz
- Endurance Performance Research Group, School of Physical Education and Sport , University of São Paulo, São Paulo, Brazil
| | - Julio Satoshi Hasegawa
- Endurance Performance Research Group, School of Physical Education and Sport , University of São Paulo, São Paulo, Brazil
| | - Arthur Fernandes Gáspari
- Laboratory of Exercise Physiology, School of Physical Education, University of Campinas, Campinas, São Paulo, Brazil
| | | | - Marcos David Silva-Cavalcante
- Endurance Performance Research Group, School of Physical Education and Sport , University of São Paulo, São Paulo, Brazil.,Faculty of Nutrition. Federal University of Alagoas, Maceio, Alagoas, Brazil
| | - Daniel Boari Coelho
- Center of Engineering, Modeling, and Applied Social Science, Federal University of ABC, Sao Paulo, Brazil
| | - Adriano E Lima-Silva
- Faculty of Nutrition. Federal University of Alagoas, Maceio, Alagoas, Brazil.,Human Performance Research Group, Federal University of Technology - Parana, Parana, Brazil
| | - Romulo Bertuzzi
- Endurance Performance Research Group, School of Physical Education and Sport , University of São Paulo, São Paulo, Brazil
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Fan JL, Wu TY, Lovering AT, Nan L, Bang WL, Kayser B. Differential Brain and Muscle Tissue Oxygenation Responses to Exercise in Tibetans Compared to Han Chinese. Front Physiol 2021; 12:617954. [PMID: 33716766 PMCID: PMC7943468 DOI: 10.3389/fphys.2021.617954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/18/2021] [Indexed: 11/13/2022] Open
Abstract
The Tibetans’ better aerobic exercise capacity at altitude remains ill-understood. We tested the hypothesis that Tibetans display better muscle and brain tissue oxygenation during exercise in hypoxia. Using near-infrared spectrometry (NIRS) to provide indices of tissue oxygenation, we measured oxy- and deoxy-hemoglobin ([O2Hb] and [HHb], respectively) responses of the vastus lateralis muscle and the right prefrontal cortex in ten Han Chinese and ten Tibetans during incremental cycling to exhaustion in a pressure-regulated chamber at simulated sea-level (air at 1 atm: normobaric normoxia) and 5,000 m (air at 0.5 atm: hypobaric hypoxia). Hypoxia reduced aerobic capacity by ∼22% in both groups (d = 0.8, p < 0.001 vs. normoxia), while Tibetans consistently outperformed their Han Chinese counterpart by ∼32% in normoxia and hypoxia (d = 1.0, p = 0.008). We found cerebral [O2Hb] was higher in Tibetans at normoxic maximal effort compared Han (p = 0.001), while muscle [O2Hb] was not different (p = 0.240). Hypoxic exercise lowered muscle [O2Hb] in Tibetans by a greater extent than in Han (interaction effect: p < 0.001 vs. normoxic exercise). Muscle [O2Hb] was lower in Tibetans when compared to Han during hypoxic exercise (d = 0.9, p = 0.003), but not during normoxic exercise (d = 0.4, p = 0.240). Muscle [HHb] was not different between the two groups during normoxic and hypoxic exercise (p = 0.778). Compared to Han, our findings revealed a higher brain tissue oxygenation in Tibetans during maximal exercise in normoxia, but lower muscle tissue oxygenation during exercise in hypoxia. This would suggest that the Tibetans privileged oxygenation of the brain at the expense of that of the muscle.
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Affiliation(s)
- Jui-Lin Fan
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Tian Yi Wu
- Research Center for High Altitude Medicine, Tibet University Medical College, Lhasa, China.,National Key Laboratory of High Altitude Medicine, Xining, China
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, OR, United States
| | - Liya Nan
- National Key Laboratory of High Altitude Medicine, Xining, China
| | - Wang Liang Bang
- National Key Laboratory of High Altitude Medicine, Xining, China
| | - Bengt Kayser
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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Fatigue development and perceived response during self-paced endurance exercise: state-of-the-art review. Eur J Appl Physiol 2021. [PMID: 33389141 DOI: 10.1007/s00421-020-04549-] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Performance in self-paced endurance exercises results from continuous fatigue symptom management. While it is suggested that perceived responses and neuromuscular fatigue development may determine variations in exercise intensity, it is uncertain how these fatigue components interact throughout the task. To address the fatigue development in self-paced endurance exercises, the following topics were addressed in the present review: (1) fatigue development during constant-load vs. self-paced endurance exercises; (2) central and peripheral fatigue and perceived exertion interconnections throughout the self-paced endurance exercises; and (3) future directions and recommendations. Based on the available literature, it is suggested (1) the work rate variations during a self-paced endurance exercise result in transitions between exercise intensity domains, directly impacting the end-exercise central and peripheral fatigue level when compared to constant-load exercise mode; (2) central and peripheral fatigue, as well as perceived exertion response contribute to exercise intensity regulation at the different stages of the trial. It seems that while neuromuscular fatigue development might be relevant at beginning of the trial, the perceived exertion might interfere in the remaining parts to achieve maximal values only at the finish line; (3) future studies should focus on the mechanisms underpinning fatigue components interactions throughout the task and its influence on exercise intensity variations.
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Brownstein CG, Millet GY, Thomas K. Neuromuscular responses to fatiguing locomotor exercise. Acta Physiol (Oxf) 2021; 231:e13533. [PMID: 32627930 DOI: 10.1111/apha.13533] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 12/26/2022]
Abstract
Over the last two decades, an abundance of research has explored the impact of fatiguing locomotor exercise on the neuromuscular system. Neurostimulation techniques have been implemented prior to and following locomotor exercise tasks of a wide variety of intensities, durations, and modes. These techniques have allowed for the assessment of alterations occurring within the central nervous system and the muscle, while techniques such as transcranial magnetic stimulation and spinal electrical stimulation have permitted further segmentalization of locomotor exercise-induced changes along the motor pathway. To this end, the present review provides a comprehensive synopsis of the literature pertaining to neuromuscular responses to locomotor exercise. Sections of the review were divided to discuss neuromuscular responses to maximal, severe, heavy and moderate intensity, high-intensity intermittent exercise, and differences in neuromuscular responses between exercise modalities. During maximal and severe intensity exercise, alterations in neuromuscular function reside primarily within the muscle. Although post-exercise reductions in voluntary activation following maximal and severe intensity exercise are generally modest, several studies have observed alterations occurring at the cortical and/or spinal level. During prolonged heavy and moderate intensity exercise, impairments in contractile function are attenuated with respect to severe intensity exercise, but are still widely observed. While reductions in voluntary activation are greater during heavy and moderate intensity exercise, the specific alterations occurring within the central nervous system remain unclear. Further work utilizing stimulation techniques during exercise and integrating new and emerging techniques such as high-density electromyography is warranted to provide further insight into neuromuscular responses to locomotor exercise.
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Affiliation(s)
- Callum G. Brownstein
- Inter‐University Laboratory of Human Movement Biology Université LyonUJM‐Saint‐Etienne Saint‐Etienne France
| | - Guillaume Y. Millet
- Inter‐University Laboratory of Human Movement Biology Université LyonUJM‐Saint‐Etienne Saint‐Etienne France
- Institut Universitaire de France (IUF) France
| | - Kevin Thomas
- Faculty of Health and Life Sciences Northumbria University Newcastle upon Tyne United Kingdom
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Constantini K, Bouillet AC, Wiggins CC, Martin BJ, Chapman RF. Ventilatory Responsiveness during Exercise and Performance Impairment in Acute Hypoxia. Med Sci Sports Exerc 2021; 53:295-305. [PMID: 32694376 PMCID: PMC8058857 DOI: 10.1249/mss.0000000000002466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION An adequate increase in minute ventilation to defend arterial oxyhemoglobin saturation (SpO2) during hypoxic exercise is commonly viewed as an important factor contributing to large inter-individual variations in the degree of exercise performance impairment in hypoxia. Although the hypoxic ventilatory response (HVR) could provide insight into the underpinnings of such impairments, it is typically measured at rest under isocapnic conditions. Thus, we aimed to determine whether 1) HVR at rest and during exercise are similar and 2) exercise HVR is related to the degree of impairment in cycling time trial (TT) performance from normoxia to acute hypoxia (∆TT). METHODS Sixteen endurance-trained men (V˙O2peak, 62.5 ± 5.8 mL·kg-1·min-1) performed two poikilocapnic HVR tests: one during seated rest (HVRREST) and another during submaximal cycling (HVREX). On two separate visits, subjects (n = 12) performed a 10-km cycling TT while breathing either room air (FiO2 = 0.21) or hypoxic gas mixture (FiO2 = 0.16) in a randomized order. RESULTS HVREX was significantly (P < 0.001) greater than HVRREST (1.52 ± 0.47 and 0.22 ± 0.13 L·min-1·%SpO2-1, respectively), and these measures were not correlated (r = -0.16, P = 0.57). ∆TT was not correlated with HVRREST (P = 0.70) or HVREX (P = 0.54), but differences in ventilation and end-tidal CO2 between hypoxic and normoxic TT and the ventilatory equivalent for CO2 during normoxic TT explained ~85% of the variance in performance impairment in acute hypoxia (P < 0.01). CONCLUSION We conclude that 1) HVR is not an appropriate measure to predict the exercise ventilatory response or performance impairments in acute hypoxia and 2) an adequate and metabolically matched increase in exercise ventilation, but not the gain in the ventilatory response to hypoxia, is essential for mitigating hypoxia-induced impairments in endurance cycling performance.
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Affiliation(s)
| | - Anna C Bouillet
- Department of Kinesiology, Indiana University, Bloomington, IN
| | - Chad C Wiggins
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
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Poole DC, Behnke BJ, Musch TI. The role of vascular function on exercise capacity in health and disease. J Physiol 2021; 599:889-910. [PMID: 31977068 PMCID: PMC7874303 DOI: 10.1113/jp278931] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/10/2019] [Indexed: 12/16/2022] Open
Abstract
Three sentinel parameters of aerobic performance are the maximal oxygen uptake ( V ̇ O 2 max ), critical power (CP) and speed of the V ̇ O 2 kinetics following exercise onset. Of these, the latter is, perhaps, the cardinal test of integrated function along the O2 transport pathway from lungs to skeletal muscle mitochondria. Fast V ̇ O 2 kinetics demands that the cardiovascular system distributes exercise-induced blood flow elevations among and within those vascular beds subserving the contracting muscle(s). Ideally, this process must occur at least as rapidly as mitochondrial metabolism elevates V ̇ O 2 . Chronic disease and ageing create an O2 delivery (i.e. blood flow × arterial [O2 ], Q ̇ O 2 ) dependency that slows V ̇ O 2 kinetics, decreasing CP and V ̇ O 2 max , increasing the O2 deficit and sowing the seeds of exercise intolerance. Exercise training, in contrast, does the opposite. Within the context of these three parameters (see Graphical Abstract), this brief review examines the training-induced plasticity of key elements in the O2 transport pathway. It asks how structural and functional vascular adaptations accelerate and redistribute muscle Q ̇ O 2 and thus defend microvascular O2 partial pressures and capillary blood-myocyte O2 diffusion across a ∼100-fold range of muscle V ̇ O 2 values. Recent discoveries, especially in the muscle microcirculation and Q ̇ O 2 -to- V ̇ O 2 heterogeneity, are integrated with the O2 transport pathway to appreciate how local and systemic vascular control helps defend V ̇ O 2 kinetics and determine CP and V ̇ O 2 max in health and how vascular dysfunction in disease predicates exercise intolerance. Finally, the latest evidence that nitrate supplementation improves vascular and therefore aerobic function in health and disease is presented.
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Affiliation(s)
- David C Poole
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Brad J Behnke
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Timothy I Musch
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
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45
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Azevedo RDA, Silva-Cavalcante MD, Lima-Silva AE, Bertuzzi R. Fatigue development and perceived response during self-paced endurance exercise: state-of-the-art review. Eur J Appl Physiol 2021; 121:687-696. [PMID: 33389141 DOI: 10.1007/s00421-020-04549-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 11/02/2020] [Indexed: 11/29/2022]
Abstract
Performance in self-paced endurance exercises results from continuous fatigue symptom management. While it is suggested that perceived responses and neuromuscular fatigue development may determine variations in exercise intensity, it is uncertain how these fatigue components interact throughout the task. To address the fatigue development in self-paced endurance exercises, the following topics were addressed in the present review: (1) fatigue development during constant-load vs. self-paced endurance exercises; (2) central and peripheral fatigue and perceived exertion interconnections throughout the self-paced endurance exercises; and (3) future directions and recommendations. Based on the available literature, it is suggested (1) the work rate variations during a self-paced endurance exercise result in transitions between exercise intensity domains, directly impacting the end-exercise central and peripheral fatigue level when compared to constant-load exercise mode; (2) central and peripheral fatigue, as well as perceived exertion response contribute to exercise intensity regulation at the different stages of the trial. It seems that while neuromuscular fatigue development might be relevant at beginning of the trial, the perceived exertion might interfere in the remaining parts to achieve maximal values only at the finish line; (3) future studies should focus on the mechanisms underpinning fatigue components interactions throughout the task and its influence on exercise intensity variations.
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Affiliation(s)
- Rafael de Almeida Azevedo
- Endurance Sports Research Group (GEDAE-USP), School of Physical Education and Sport, University of Sao Paulo, Av. Prof. Mello Moraes, 65 - Cidade Universitária, São Paulo, SP, 05508-030, Brazil
| | - Marcos David Silva-Cavalcante
- Endurance Sports Research Group (GEDAE-USP), School of Physical Education and Sport, University of Sao Paulo, Av. Prof. Mello Moraes, 65 - Cidade Universitária, São Paulo, SP, 05508-030, Brazil.,Sport Science Research Group, Post-Graduation Program Nutrition, Physical Activity and Phenotypic Plasticity, Academic Center of Vitoria, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Adriano Eduardo Lima-Silva
- Human Performance Research Group, Federal University of Technology - Parana (UTFPR), Curitiba, Parana, Brazil
| | - Romulo Bertuzzi
- Endurance Sports Research Group (GEDAE-USP), School of Physical Education and Sport, University of Sao Paulo, Av. Prof. Mello Moraes, 65 - Cidade Universitária, São Paulo, SP, 05508-030, Brazil.
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Hinde KL, Low C, Lloyd R, Cooke CB. Inspiratory muscle training at sea level improves the strength of inspiratory muscles during load carriage in cold-hypoxia. ERGONOMICS 2020; 63:1584-1598. [PMID: 32812837 DOI: 10.1080/00140139.2020.1807613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Inspiratory muscle training (IMT) and functional IMT (IMTF: exercise-specific IMT activities) has been unsuccessful in reducing respiratory muscle fatigue following load carriage. IMTF did not include load carriage specific exercises. Fifteen participants split into two groups (training and control) walked 6 km loaded (18.2 kg) at speeds representing ∼50%V̇O2max in cold-hypoxia. The walk was completed at baseline; post 4 weeks IMT and 4 weeks IMTF (five exercises engaging core muscles, three involved load). The training group completed IMT and IMTF at a higher maximal inspiratory pressure (Pimax) than controls. Improvements in Pimax were greater in the training group post-IMT (20.4%, p = .025) and post-IMTF (29.1%, p = .050) compared to controls. Respiratory muscle fatigue was unchanged (p = .643). No other physiological or subjective measures were improved by IMT or IMTF. Both IMT and IMTF increased the strength of respiratory muscles pre-and-post a 6 km loaded walk in cold-hypoxia. Practitioner Summary: To explore the interaction between inspiratory muscle training (IMT), load carriage and environment, this study investigated 4 weeks IMT and 4 weeks functional IMT on respiratory muscle strength and fatigue. Functional IMT improved inspiratory muscle strength pre-and-post a loaded walk in cold-hypoxia but had no more effect than IMT alone. Abbreviations: ANOVA: analysis of variance; BF: breathing frequency; CON: control group; EELV: end-expiratory lung volume; EXP: experimental group; FEV1: forced expiratory volume in one second; FiO2: fraction of inspired oxygen; FVC: forced vital capacity; HR: heart rate; IMT: inspiratory muscle training; IMTF: functional inspiratory muscle training; Pemax: maximal expiratory pressure; Pimax: maximal inspiratory pressure; RMF: respiratory muscle fatigue; RPE: rate of perceived exertion; RWU: respiratory muscle warm-up; SaO2: arterial oxygen saturation; SpO2: peripheral oxygen saturation; V̇E: minute ventilation; V̇O2: rate of oxygen uptake.
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Affiliation(s)
- K L Hinde
- Defence Science and Technology Laboratory, Salisbury, UK
- Carnegie School of Sport, Leeds Beckett University, Leeds, UK
| | - C Low
- Carnegie School of Sport, Leeds Beckett University, Leeds, UK
| | - R Lloyd
- School of Social and Health Sciences, Leeds Trinity University, Leeds, UK
| | - C B Cooke
- School of Social and Health Sciences, Leeds Trinity University, Leeds, UK
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Zarzissi S, Bouzid MA, Zghal F, Rebai H, Hureau TJ. Aging reduces the maximal level of peripheral fatigue tolerable and impairs exercise capacity. Am J Physiol Regul Integr Comp Physiol 2020; 319:R617-R625. [PMID: 32966120 DOI: 10.1152/ajpregu.00151.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The aim of the present study was to determine the magnitude of the maximal level of peripheral fatigue attainable (fatigue threshold) during an all-out intermittent isometric knee-extensor protocol in both younger (24 ± 1 yr, n = 12) and older (60 ± 2 yr, n = 12) participants to provide new insights into the effects of aging on neuromuscular function. Participants performed two experimental sessions, in which they performed 60 maximal voluntary contractions (MVCs; 3 s of contraction, 2 s of relaxation). One trial was performed in the unfatigued state (CTRL) and one other following fatiguing neuromuscular electrical stimulation of the quadriceps (FNMES). Peripheral fatigue was quantified via pre/postexercise decrease in quadriceps twitch force (∆Ptw). Critical force (CF) was determined as the mean force output of the last 12 contractions, whereas W' was calculated as the area above CF. Although FNMES led to a significant decrease in Ptw before performing the 60-MVCs protocol (P = 0.024), ∆Ptw was not different between CTRL and FNMES for both the young group (P = 0.491) and the old group (P = 0.523). However, this peripheral fatigue threshold was significantly greater in young versus old participants (∆Ptw = -48 ± 10% vs. -29 ± 13%, respectively, P = 0.028). In CTRL, W' was 55 ± 13% lower in the old group than in the young group (P < 0.001), but CF was similar (326 ± 10 N vs. 322 ± 12 N, respectively, P = 0.941). ∆Ptw was correlated with W', independently of age (r2 = 0.84, P < 0.001). Exercise performance decreases with aging consequent to a lower tolerance to peripheral fatigue. However, the peripheral fatigue threshold mechanism persists with healthy aging and continues to play a protective role in preserving locomotor muscle function during exercise.
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Affiliation(s)
- Slim Zarzissi
- Education, Motor Skills, Sport and Health Laboratory, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia
| | - Mohamed Amine Bouzid
- Education, Motor Skills, Sport and Health Laboratory, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia
| | - Firas Zghal
- Education, Motor Skills, Sport and Health Laboratory, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia
| | - Haithem Rebai
- Education, Motor Skills, Sport and Health Laboratory, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia
| | - Thomas J Hureau
- Mitochondria, Oxidative Stress and Muscular Protection Laboratory (UR 3072), Faculty of Medicine, University of Strasbourg, Strasbourg, France.,European Centre for Education, Research and Innovation in Exercise Physiology (CEERIPE), Faculty of Sport Sciences, University of Strasbourg, Strasbourg, France
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48
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Hammer SM, Alexander AM, Didier KD, Barstow TJ. Influence of blood flow occlusion on muscular recruitment and fatigue during maximal‐effort small muscle‐mass exercise. J Physiol 2020; 598:4293-4306. [DOI: 10.1113/jp279925] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/22/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Shane M. Hammer
- Department of Kinesiology Kansas State University Manhattan KS USA
| | | | - Kaylin D. Didier
- Department of Kinesiology Kansas State University Manhattan KS USA
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Ferreira GA, Felippe LC, Silva-Cavalcante MD, De-Mello APA, Coelho DB, Maranhão R, Bertuzzi R, Dolinsky M, De-Oliveira FR, Lima-Silva AE, Da-Silva KJ. Maytenus ilicifolia Extract Increases Oxygen Uptake without Changes in Neuromuscular Fatigue Development during a High-Intensity Interval Exercise. J Am Coll Nutr 2020; 40:419-428. [PMID: 32790496 DOI: 10.1080/07315724.2020.1787906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE We investigated the effects of acute ingestion of Maytenus ilicifolia extract on metabolic and cardiopulmonary responses during a high-intensity interval exercise (HIIE), and its consequence on neuromuscular fatigue. METHODS Ten healthy men underwent a HIIE (4 x 4 min, 3 min recovery) one hour after ingesting 400 mg of Maytenus ilicifolia extract (MIE) or placebo. Oxygen uptake (V̇O2), dioxide carbon production (V̇CO2), ventilation (V̇E) and heart rate (HR) were measured throughout the HIIE. Maximal voluntary contraction (MVC), voluntary activation (VA), and evoked 1, 10 and 100 Hz force twitch were measured before supplementation (baseline), and before (pre-HIIE) and after the HIIE (post-HIIE). RESULTS The V̇O2, V̇E, V̇E/V̇O2 ratio and HR increased progressively throughout the HIIE under both conditions (p < 0.05). MIE increased HR, however, at bouts 1 and 2 and mean V̇O2 during HIIE. The mean respiratory exchange ratio during recovery was also reduced with MIE (p < 0.05). MVC and evoked force at 1, 10 and 100 Hz declined similarly after HIIE, regardless of the condition (MIE: -18 ± 17%, -50 ± 15%, -61 ± 13% and -34 ± 10% vs. placebo: -19 ± 15%, -48 ± 16%, -58 ± 12 and -29 ± 11%, respectively, p < 0.05). There was no effect of exercise or MIE on VA (p > 0.05). CONCLUSION MIE increases heart rate in the first bouts and mean oxygen uptake during HIIE without changes in neuromuscular fatigue development.
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Affiliation(s)
- Guilherme A Ferreira
- Associated Program of Post-Graduation in Physical Education UPE/UFPB, University of Pernambuco, Recife, Brazil.,Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology - Parana (UTFPR), Curitiba, Brazil
| | - Leandro C Felippe
- Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology - Parana (UTFPR), Curitiba, Brazil
| | - Marcos D Silva-Cavalcante
- Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology - Parana (UTFPR), Curitiba, Brazil
| | - Ana Paula A De-Mello
- Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Pernambuco, Brazil
| | - Daniel B Coelho
- Center of Engineering, Modeling, and Applied Social Science, Federal University of ABC, São Paulo, São Paulo, Brazil
| | - Renato Maranhão
- Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Pernambuco, Brazil
| | - Rômulo Bertuzzi
- Endurance Performance Research Group (GEDAE-USP), University of São Paulo, São Paulo, Brazil
| | - Manuela Dolinsky
- Departament of Nutrition and Dietetic, Federal Fluminense University, Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Adriano E Lima-Silva
- Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology - Parana (UTFPR), Curitiba, Brazil
| | - Kleber J Da-Silva
- Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Pernambuco, Brazil.,Human Performance Research Group, Federal University of Technology - Parana (UTFPR), Curitiba, Brazil
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50
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Abstract
This study aimed to compare selected hormonal responses to a single session of high intensity interval training performed with an increased fraction of inspired oxygen (hyperoxia) and under normoxic conditions. Twelve recreationally trained men (age 24 ± 3 years) performed two sessions of high intensity interval training on a cycle ergometer, in randomized order with hyperoxia (4 L·min-1 with a flowrate of 94% O2) and normoxia. Each session consisted of 5 intervals of 3 minutes at 85% of the maximal power output, interspersed by 2 min at 40% of the maximal power output. Serum cortisol, prolactin and vascular endothelial growth factor (VEGF) were assessed both before and immediately after each high intensity interval training session. Statistically significant differences in cortisol were found between hyperoxic and normoxic conditions (p = 0.011), with a significant increase in hyperoxia (61.4 ± 73.2%, p = 0.013, ES = -1.03), but not in normoxia (-1.3 ± 33.5%, p > 0.05, ES = 0.1). Prolactin increased similarly in both hyperoxia (118.1 ± 145.1%, p = 0.019, ES = -0.99) and normoxia (62.14 ± 75.43%, p = 0.005, ES = -0.5). VEGF was not statistically altered in either of the conditions. Our findings indicate that a single session of high intensity interval training in low-dose hyperoxia significantly increased cortisol concentrations in recreationally trained individuals compared to normoxia, while the difference was smaller in prolactin and diminished in VEGF concentrations.
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