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Stavres J, Aultman RS, Newsome TA. Exercise pressor responses are exaggerated relative to force production during, but not following, thirty-minutes of rhythmic handgrip exercise. Eur J Appl Physiol 2024; 124:1547-1559. [PMID: 38155209 DOI: 10.1007/s00421-023-05390-2] [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: 08/03/2023] [Accepted: 11/29/2023] [Indexed: 12/30/2023]
Abstract
PURPOSE This study tested the hypothesis that blood pressure responses would increase relative to force production in response to prolonged bouts of muscular work. METHODS Fifteen individuals performed two minutes of static handgrip (SHG; 35% MVC), followed by three minutes of post-exercise-cuff-occlusion (PECO), before and after thirty minutes of rest (control), or rhythmic handgrip exercise (RHG) of the contralateral and ipsilateral forearms. Beat-by-beat recordings of mean arterial pressure (MAP), heart rate (HR), and handgrip force (kg) were averaged across one-minute periods at baseline, and minutes 5, 10, 15, 20, 25, and 30 of RHG. MAP was also normalized to handgrip force, providing a relative measure of exercise pressor responses (mmHg/kg). Hemodynamic responses to SHG and PECO were also compared before and after contralateral RHG, ipsilateral RHG, and control, respectively. Similar to the RHG trial, areas under the curve were calculated for MAP (blood pressure index; BPI) and normalized to the time tension index (BPInorm). RESULTS HR and MAP significantly increased during RHG (15.3 ± 1.4% and 20.4 ± 3.2%, respectively, both p < 0.01), while force output decreased by up to 36.6 ± 8.0% (p < 0.01). This resulted in a 51.6 ± 9.4% increase in BPInorm during 30 min of RHG (p < 0.01). In contrast, blood pressure responses to SHG and PECO were unchanged following RHG (all p ≥ 0.07), and only the mean HR (4.2 ± 1.5%, p = 0.01) and ΔHR (67.2 ± 18.1%, p < 0.01) response to SHG were exaggerated following ipsilateral RHG. CONCLUSIONS The magnitude of exercise pressor responses relative to force production progressively increases during, but not following, prolonged bouts of muscular work.
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Affiliation(s)
- Jon Stavres
- School of Kinesiology and Nutrition, University of Southern Mississippi, 118 College Drive, Hattiesburg, MS, USA.
| | - Ryan S Aultman
- School of Kinesiology and Nutrition, University of Southern Mississippi, 118 College Drive, Hattiesburg, MS, USA
| | - Ta'Quoris A Newsome
- School of Kinesiology and Nutrition, University of Southern Mississippi, 118 College Drive, Hattiesburg, MS, USA
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2
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Fekih N, Zghal F, Machfer A, Ben Hadj Hassen H, Zarizissi S, Bouzid MA. Peripheral fatigue regulation during knee extensor exercise in type 1 diabetes and consequences on the force-duration relationship. Eur J Appl Physiol 2024; 124:897-908. [PMID: 37733138 DOI: 10.1007/s00421-023-05318-w] [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: 04/26/2023] [Accepted: 09/04/2023] [Indexed: 09/22/2023]
Abstract
PURPOSE This study aimed to examine if peripheral fatigue is adjusted during knee extensor (KE) exercise in order not to surpass a critical threshold patient with type 1 diabetes (T1D) and the consequences of this mechanism on the force-duration relationship. METHODS Eleven T1D individuals randomly performed two different sessions in which they performed 60 maximum voluntary contractions (MVC; 3 s contraction, 2 s relaxation). One trial was performed in the non-fatigued state (CTRL) and another after fatiguing neuromuscular stimulation of the KE (FNMES). Peripheral and central fatigue were quantified by the difference between pre and post exercise in quadriceps voluntary activation (ΔVA) and potentiated twitch (ΔPtw). Critical torque (CT) was determined as the average force of the last 12 contractions, whereas W' was calculated as the area above the CT. RESULTS Although FNMES led to a significant decrease in potentiated twitch (Ptw) before performing the 60-MVCs protocol (p < 0.05), ΔVA (∼ -7.5%), ΔPtw (∼ -39%), and CT (∼816 N) post-MVCs were similar between the two conditions. The difference in W' between CTRL and FNMES was correlated with the level of pre-fatigue induced in FNMES (r2 = 0.60). In addition, W' was correlated with ΔPtw (r2 = 0.62) in the CTRL session. CONCLUSION Correlative results in the present study indicate that regulating peripheral fatigue mechanisms at a critical threshold limit W'. Additionally, peripheral fatigue during KE exercise is limited to an individual threshold in T1D patients.
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Affiliation(s)
- Nadia Fekih
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Road of the Aerodrome, Km 3.5, BP 1068, 3000, Sfax, Tunisia
| | - Firas Zghal
- Faculté des Sciences du Sport, LAMHESS, Université Côte d'Azur, Nice, France
| | - Amal Machfer
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Road of the Aerodrome, Km 3.5, BP 1068, 3000, Sfax, Tunisia
| | - Hayfa Ben Hadj Hassen
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Road of the Aerodrome, Km 3.5, BP 1068, 3000, Sfax, Tunisia
| | - Slim Zarizissi
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Road of the Aerodrome, Km 3.5, BP 1068, 3000, Sfax, Tunisia
| | - Mohamed Amine Bouzid
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Road of the Aerodrome, Km 3.5, BP 1068, 3000, Sfax, Tunisia.
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Tankisi H, Versace V, Kuppuswamy A, Cole J. The role of clinical neurophysiology in the definition and assessment of fatigue and fatigability. Clin Neurophysiol Pract 2023; 9:39-50. [PMID: 38274859 PMCID: PMC10808861 DOI: 10.1016/j.cnp.2023.12.004] [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: 05/01/2023] [Revised: 11/24/2023] [Accepted: 12/07/2023] [Indexed: 01/27/2024] Open
Abstract
Though a common symptom, fatigue is difficult to define and investigate, occurs in a wide variety of neurological and systemic disorders, with differing pathological causes. It is also often accompanied by a psychological component. As a symptom of long-term COVID-19 it has gained more attention. In this review, we begin by differentiating fatigue, a perception, from fatigability, quantifiable through biomarkers. Central and peripheral nervous system and muscle disorders associated with these are summarised. We provide a comprehensive and objective framework to help identify potential causes of fatigue and fatigability in a given disease condition. It also considers the effectiveness of neurophysiological tests as objective biomarkers for its assessment. Among these, twitch interpolation, motor cortex stimulation, electroencephalography and magnetencephalography, and readiness potentials will be described for the assessment of central fatigability, and surface and needle electromyography (EMG), single fibre EMG and nerve conduction studies for the assessment of peripheral fatigability. The purpose of this review is to guide clinicians in how to approach fatigue, and fatigability, and to suggest that neurophysiological tests may allow an understanding of their origin and interactions. In this way, their differing types and origins, and hence their possible differing treatments, may also be defined more clearly.
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Affiliation(s)
- Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
- Institute of Clinical Medicine, Aarhus University, Denmark
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Teaching Hospital of the Paracelsus Medical Private University (PMU), Vipiteno-Sterzing, Italy
| | - Annapoorna Kuppuswamy
- Department of Clinical and Movement Neuroscience, Institute of Neurology, University College London, WC1N 3BG London, UK
- Department of Biomedical Sciences, University of Leeds, UK
| | - Jonathan Cole
- Clinical Neurophysiology, University Hospitals Dorset (Poole), UK
- University of Bournemouth, Poole, UK
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4
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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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Cherouveim ED, Miliotis PG, Koskolou MD, Dipla K, Vrabas IS, Geladas ND. The Effect of Skeletal Muscle Oxygenation on Hemodynamics, Cerebral Oxygenation and Activation, and Exercise Performance during Incremental Exercise to Exhaustion in Male Cyclists. BIOLOGY 2023; 12:981. [PMID: 37508410 PMCID: PMC10376807 DOI: 10.3390/biology12070981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/28/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023]
Abstract
This study aimed to elucidate whether muscle blood flow restriction during maximal exercise is associated with alterations in hemodynamics, cerebral oxygenation, cerebral activation, and deterioration of exercise performance in male participants. Thirteen healthy males, cyclists (age 33 ± 2 yrs., body mass: 78.6 ± 2.5 kg, and body mass index: 25.57 ± 0.91 kg·m-1), performed a maximal incremental exercise test on a bicycle ergometer in two experimental conditions: (a) with muscle blood flow restriction through the application of thigh cuffs inflated at 120 mmHg (with cuffs, WC) and (b) without restriction (no cuffs, NC). Exercise performance significantly deteriorated with muscle blood flow restriction, as evidenced by the reductions in V˙O2max (-17 ± 2%, p < 0.001), peak power output (-28 ± 2%, p < 0.001), and time to exhaustion (-28 ± 2%, p < 0.001). Muscle oxygenated hemoglobin (Δ[O2Hb]) during exercise declined more in the NC condition (p < 0.01); however, at exhaustion, the magnitude of muscle oxygenation and muscle deoxygenation were similar between conditions (p > 0.05). At maximal effort, lower cerebral deoxygenated hemoglobin (Δ[HHb]) and cerebral total hemoglobin (Δ[THb]) were observed in WC (p < 0.001), accompanied by a lower cardiac output, heart rate, and stroke volume vs. the NC condition (p < 0.01), whereas systolic blood pressure, rating of perceived exertion, and cerebral activation (as assessed by electroencephalography (EEG) activity) were similar (p > 0.05) between conditions at task failure, despite marked differences in exercise duration, maximal aerobic power output, and V˙O2max. In conclusion, in trained cyclists, muscle blood flow restriction during an incremental cycling exercise test significantly limited exercise performance. Exercise intolerance with muscle blood flow restriction was mainly associated with attenuated cardiac responses, despite cerebral activation reaching similar maximal levels as without muscle blood flow restriction.
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Affiliation(s)
- Evgenia D Cherouveim
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
| | - Panagiotis G Miliotis
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
| | - Maria D Koskolou
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
| | - Konstantina Dipla
- Laboratory of Exercise Physiology and Biochemistry, School of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, 62122 Serres, Greece
| | - Ioannis S Vrabas
- Laboratory of Exercise Physiology and Biochemistry, School of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, 62122 Serres, Greece
| | - Nickos D Geladas
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
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6
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Mallard J, Hucteau E, Schott R, Trensz P, Pflumio C, Kalish-Weindling M, Favret F, Pivot X, Hureau TJ, Pagano AF. Early skeletal muscle deconditioning and reduced exercise capacity during (neo)adjuvant chemotherapy in patients with breast cancer. Cancer 2023; 129:215-225. [PMID: 36397290 PMCID: PMC10099272 DOI: 10.1002/cncr.34533] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/17/2022] [Accepted: 10/06/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND Fatigue is a hallmark of breast cancer and is associated with skeletal muscle deconditioning. If cancer-related fatigue occurs early during chemotherapy (CT), the development of skeletal muscle deconditioning and its effect on exercise capacity remain unclear. The aim of this study was to investigate the evolution of skeletal muscle deconditioning and exercise capacity in patients with early-stage breast cancer during CT. METHODS Patients with breast cancer had a visit before undergoing CT, at 8 weeks, and at the end of chemotherapy (post-CT). Body composition was determined through bioelectrical impedance analysis. Knee extensor, handgrip muscle force and fatigue was quantified by performing maximal voluntary isometric contractions and exercise capacity using the 6-min walking test. Questionnaires were also administered to evaluate quality of life, cancer-related fatigue, and physical activity level. RESULTS Among the 100 patients, reductions were found in muscle mass (-2.3%, p = .002), exercise capacity (-6.7%, p < .001), and knee extensor force (-4.9%, p < .001) post-CT, which occurred within the first 8 weeks of treatment with no further decrease thereafter. If muscle fatigue did not change, handgrip muscle force decreased post-CT only (-2.5%, p = .001), and exercise capacity continued to decrease between 8 weeks and post-CT (-4.6%, p < .001). Quality of life and cancer-related fatigue were impaired after 8 weeks (p < .001) and remained stable thereafter, whereas the physical activity level remained stable during chemotherapy. CONCLUSIONS Similar to cancer-related fatigue, skeletal muscle deconditioning and reduced exercise capacity occurred early during breast cancer CT. Thus, it appears essential to prevent these alterations through exercise training implemented during CT.
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Affiliation(s)
- Joris Mallard
- Biomedicine Research Centre of Strasbourg (CRBS), Mitochondria, oxidative stress, and muscular protection laboratory (UR 3072), Strasbourg, France.,Faculty of Sport Sciences, European Centre for Education, Research and Innovation in Exercise Physiology (CEERIPE), University of Strasbourg, Strasbourg, France.,Institute of Cancerology Strasbourg Europe (ICANS), Strasbourg, France
| | - Elyse Hucteau
- Biomedicine Research Centre of Strasbourg (CRBS), Mitochondria, oxidative stress, and muscular protection laboratory (UR 3072), Strasbourg, France.,Faculty of Sport Sciences, European Centre for Education, Research and Innovation in Exercise Physiology (CEERIPE), University of Strasbourg, Strasbourg, France.,Institute of Cancerology Strasbourg Europe (ICANS), Strasbourg, France
| | - Roland Schott
- Institute of Cancerology Strasbourg Europe (ICANS), Strasbourg, France
| | - Philippe Trensz
- Institute of Cancerology Strasbourg Europe (ICANS), Strasbourg, France
| | - Carole Pflumio
- Institute of Cancerology Strasbourg Europe (ICANS), Strasbourg, France
| | | | - Fabrice Favret
- Biomedicine Research Centre of Strasbourg (CRBS), Mitochondria, oxidative stress, and muscular protection laboratory (UR 3072), Strasbourg, France.,Faculty of Sport Sciences, European Centre for Education, Research and Innovation in Exercise Physiology (CEERIPE), University of Strasbourg, Strasbourg, France
| | - Xavier Pivot
- Institute of Cancerology Strasbourg Europe (ICANS), Strasbourg, France
| | - Thomas J Hureau
- Biomedicine Research Centre of Strasbourg (CRBS), Mitochondria, oxidative stress, and muscular protection laboratory (UR 3072), Strasbourg, France.,Faculty of Sport Sciences, European Centre for Education, Research and Innovation in Exercise Physiology (CEERIPE), University of Strasbourg, Strasbourg, France
| | - Allan F Pagano
- Biomedicine Research Centre of Strasbourg (CRBS), Mitochondria, oxidative stress, and muscular protection laboratory (UR 3072), Strasbourg, France.,Faculty of Sport Sciences, European Centre for Education, Research and Innovation in Exercise Physiology (CEERIPE), University of Strasbourg, Strasbourg, France
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7
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Stavres J, Luck JC, Hamaoka T, Blaha C, Cauffman A, Dalton PC, Herr MD, Ruiz-Velasco V, Carr ZJ, Janicki P, Cui J. A 10-mg dose of amiloride increases time to failure during blood-flow-restricted plantar flexion in healthy adults without influencing blood pressure. Am J Physiol Regul Integr Comp Physiol 2022; 323:R875-R888. [PMID: 36222880 PMCID: PMC9678418 DOI: 10.1152/ajpregu.00190.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/22/2022] [Accepted: 10/05/2022] [Indexed: 11/22/2022]
Abstract
Amiloride has been shown to inhibit acid-sensing ion channels (ASICs), which contribute to ischemia-related muscle pain during exercise. The purpose of this study was to determine if a single oral dose of amiloride would improve exercise tolerance and attenuate blood pressure during blood-flow-restricted (BFR) exercise in healthy adults. Ten subjects (4 females) performed isometric plantar flexion exercise with BFR (30% maximal voluntary contraction) after ingesting either a 10-mg dose of amiloride or a volume-matched placebo (random order). Time to failure, time-tension index (TTI), and perceived pain (visual analog scale) were compared between the amiloride and placebo trials. Mean blood pressure, heart rate, blood pressure index (BPI), and BPI normalized to TTI (BPInorm) were also compared between trials using both time-matched (TM50 and TM100) and effort-matched (T50 and T100) comparisons. Time to failure (+69.4 ± 63.2 s, P < 0.01) and TTI (+1,441 ± 633 kg·s, P = 0.02) were both significantly increased in the amiloride trial compared with placebo, despite no increase in pain (+0.4 ± 1.7 cm, P = 0.46). In contrast, amiloride had no significant influence on the mean blood pressure or heart rate responses, nor were there any significant differences in BPI or BPInorm between trials when matched for time (all P ≥ 0.13). When matched for effort, BPI was significantly greater in the amiloride trial (+5,300 ± 1,798 mmHg·s, P = 0.01), likely owing to an increase in total exercise duration. In conclusion, a 10-mg oral dose of amiloride appears to significantly improve the tolerance to BFR exercise in healthy adults without influencing blood pressure responses.
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Affiliation(s)
- Jon Stavres
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, Mississippi
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - J Carter Luck
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Takuto Hamaoka
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Cheryl Blaha
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Aimee Cauffman
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Paul C Dalton
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Michael D Herr
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Victor Ruiz-Velasco
- Department of Anesthesiology and Perioperative Medicine, Penn State University College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Zyad J Carr
- Department of Anesthesiology, Yale School of Medicine, Yale New Haven Hospital, New Haven, Connecticut
| | - Piotr Janicki
- Department of Anesthesiology and Perioperative Medicine, Penn State University College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Jian Cui
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania
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Laginestra FG, Cavicchia A, Vanegas-Lopez JE, Barbi C, Martignon C, Giuriato G, Pedrinolla A, Amann M, Hureau TJ, Venturelli M. Prior Involvement of Central Motor Drive Does Not Impact Performance and Neuromuscular Fatigue in a Subsequent Endurance Task. Med Sci Sports Exerc 2022; 54:1751-1760. [PMID: 35612382 PMCID: PMC9481724 DOI: 10.1249/mss.0000000000002965] [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
PURPOSE This study evaluated whether central motor drive during fatiguing exercise plays a role in determining performance and the development of neuromuscular fatigue during a subsequent endurance task. METHODS On separate days, 10 males completed three constant-load (80% peak power output), single-leg knee-extension trials to task failure in a randomized fashion. One trial was performed without preexisting quadriceps fatigue (CON), and two trials were performed with preexisting quadriceps fatigue induced either by voluntary (VOL; involving central motor drive) or electrically evoked (EVO; without central motor drive) quadriceps contractions (~20% maximal voluntary contraction (MVC)). Neuromuscular fatigue was assessed via pre-post changes in MVC, voluntary activation (VA), and quadriceps potentiated twitch force ( Qtw,pot ). Cardiorespiratory responses and rating of perceived exertion were also collected throughout the sessions. The two prefatiguing protocols were matched for peripheral fatigue and stopped when Qtw,pot declined by ~35%. RESULTS Time to exhaustion was shorter in EVO (4.3 ± 1.3 min) and VOL (4.7 ± 1.5 min) compared with CON (10.8 ± 3.6 min, P < 0.01) with no difference between EVO and VOL. ΔMVC (EVO: -47% ± 8%, VOL: -45% ± 8%, CON: -53% ± 8%), Δ Qtw,pot (EVO: -65% ± 7%, VOL: -59% ± 14%, CON: -64% ± 9%), and ΔVA (EVO: -9% ± 7%, VOL: -8% ± 5%, CON: -7% ± 5%) at the end of the dynamic task were not different between conditions (all P > 0.05). Compared with EVO (10.6 ± 1.7) and CON (6.8 ± 0.8), rating of perceived exertion was higher ( P = 0.05) at the beginning of VOL (12.2 ± 1.0). CONCLUSIONS These results suggest that central motor drive involvement during prior exercise plays a negligible role on the subsequent endurance performance. Therefore, our findings indicate that peripheral fatigue-mediated impairments are the primary determinants of high-intensity single-leg endurance performance.
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Affiliation(s)
| | - Alessandro Cavicchia
- Department of Neuroscience, Biomedicine, and Movement, University of Verona, ITALY
| | - Jennifer E. Vanegas-Lopez
- Faculty of Medicine, Mitochondria, Oxidative Stress and Muscular Protection Laboratory, University of Strasbourg, FRANCE
| | - Chiara Barbi
- Department of Neuroscience, Biomedicine, and Movement, University of Verona, ITALY
| | - Camilla Martignon
- Department of Neuroscience, Biomedicine, and Movement, University of Verona, ITALY
| | - Gaia Giuriato
- Department of Neuroscience, Biomedicine, and Movement, University of Verona, ITALY
| | - Anna Pedrinolla
- Department of Neuroscience, Biomedicine, and Movement, University of Verona, ITALY
| | - Markus Amann
- Department of Anaesthesiology, University of Utah, Salt Lake City, Utah
| | - Thomas J. Hureau
- Faculty of Medicine, Mitochondria, Oxidative Stress and Muscular Protection Laboratory, University of Strasbourg, FRANCE
| | - Massimo Venturelli
- Department of Neuroscience, Biomedicine, and Movement, University of Verona, ITALY
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9
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Hureau TJ, Broxterman RM, Weavil JC, Lewis MT, Layec G, Amann M. On the role of skeletal muscle acidosis and inorganic phosphates as determinants of central and peripheral fatigue: A 31 P-MRS study. J Physiol 2022; 600:3069-3081. [PMID: 35593645 DOI: 10.1113/jp283036] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/28/2022] [Indexed: 01/20/2023] Open
Abstract
Intramuscular hydrogen ion (H+ ) and inorganic phosphate (Pi) concentrations were dissociated during exercise to challenge their relationships with peripheral and central fatigue in vivo. Ten recreationally active, healthy men (27 ± 5 years; 180 ± 4 cm; 76 ± 10 kg) performed two consecutive intermittent isometric single-leg knee-extensor trials (60 maximal voluntary contractions; 3 s contraction, 2 s relaxation) interspersed with 5 min of rest. Phosphorus magnetic resonance spectroscopy (31 P-MRS) was used to continuously quantify intramuscular [H+ ] and [Pi] during both trials. Using electrical femoral nerve stimulation, quadriceps twitch force (Qtw ) and voluntary activation (VA) were quantified at rest and throughout both trials. Decreases in Qtw and VA from baseline were used to determine peripheral and central fatigue, respectively. Qtw was strongly related to both [H+ ] (β coefficient: -0.9, P < 0.0001) and [Pi] (-1.1, P < 0.0001) across trials. There was an effect of trial on the relationship between Qtw and [H+ ] (-0.5, P < 0.0001), but not Qtw and [Pi] (0.0, P = 0.976). This suggests that, unlike the unaltered association with [Pi], a given level of peripheral fatigue was associated with a different [H+ ] in Trial 1 vs. Trial 2. VA was related to [H+ ] (-0.3, P < 0.0001), but not [Pi] (-0.2, P = 0.243), across trials and there was no effect of trial (-0.1, P = 0.483). Taken together, these results support intramuscular Pi as a primary cause of peripheral fatigue, and muscle acidosis, probably acting on group III/IV muscle afferents in the interstitial space, as a contributor to central fatigue during exercise. KEY POINTS: We investigated the relationship between intramuscular metabolites and neuromuscular function in humans performing two maximal, intermittent, knee-extension trials interspersed with 5 min of rest. Concomitant measurements of intramuscular hydrogen (H+ ) and inorganic phosphate (Pi) concentrations, as well as quadriceps twitch-force (Qtw ) and voluntary activation (VA), were made throughout each trial using phosphorus magnetic resonance spectroscopy (31 P-MRS) and electrical femoral nerve stimulations. Although [Pi] fully recovered prior to the onset of the second trial, [H+ ] did not. Qtw was strongly related to both [H+ ] and [Pi] across both trials. However, the relationship between Qtw and [H+ ] shifted leftward from the first to the second trial, whereas the relationship between Qtw and [Pi] remained unaltered. VA was related to [H+ ], but not [Pi], across both trials. These in vivo findings support the hypotheses of intramuscular Pi as a primary cause of peripheral fatigue, and muscle acidosis, probably acting on group III/IV muscle afferents, as a contributor to central fatigue.
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Affiliation(s)
- Thomas J Hureau
- Department of Medicine, University of Utah, Salt Lake City, UT, USA.,University of Strasbourg, Faculty of Sport Sciences, UR 3072: Mitochondria, Oxidative Stress and Muscular Protection Laboratory, Strasbourg, France
| | - Ryan M Broxterman
- Department of Medicine, University of Utah, Salt Lake City, UT, USA.,Geriatric Research, Education, and Clinical Center, Salt Lake City, UT, VAMC, USA
| | - Joshua C Weavil
- Department of Medicine, University of Utah, Salt Lake City, UT, USA.,Geriatric Research, Education, and Clinical Center, Salt Lake City, UT, VAMC, USA
| | - Matthew T Lewis
- Department of Medicine, University of Utah, Salt Lake City, UT, USA.,Geriatric Research, Education, and Clinical Center, Salt Lake City, UT, VAMC, USA
| | - Gwenael Layec
- Department of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Markus Amann
- Department of Medicine, University of Utah, Salt Lake City, UT, USA.,Geriatric Research, Education, and Clinical Center, Salt Lake City, UT, VAMC, USA.,Department of Anesthesiology, University of Utah, Salt Lake City, UT, USA
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10
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de Almeida Azevedo R, Jazayeri D, Yeung ST, Khoshreza R, Millet GY, Murias JM, Aboodarda SJ. The effects of pain induced by blood flow occlusion in one leg on exercise tolerance and corticospinal excitability and inhibition of the contralateral leg in males. Appl Physiol Nutr Metab 2022; 47:632-648. [PMID: 35201916 DOI: 10.1139/apnm-2021-0597] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Experiencing pain in one leg can alter exercise tolerance and neuromuscular fatigue (NMF) responses in the contralateral leg; however, the corticospinal modulations to non-local experimental pain induced by blood flow occlusion remain unknown. In three randomized visits, thirteen male participants performed 25% of isometric maximal voluntary contraction (25%IMVC) to task failure with one leg preceded by (i) 6-min rest (CON), (ii) cycling at 80% of peak power output until task failure with the contralateral leg (CYCL) or (iii) CYCL followed by blood flow occlusion (OCCL) during 25%IMVC. NMF assessments (IMVC, voluntary activation [VA] and potentiated twitch [Qtw]) were performed at baseline and task failure. During the 25%IMVC, transcranial magnetic stimulations were performed to obtain motor evoked potential (MEP), silent period (SP), and short intracortical inhibition (SICI). 25%IMVC was shortest in OCCL (105±50s) and shorter in CYCL (154±68s) than CON (219±105s) (P<0.05). IMVC declined less after OCCL (-24±19%) and CYCL (-27±18%) then CON (-35±11%) (P<0.05). Qtw declined less in OCCL (-40±25%) compared to CYCL (-50±22%) and CON (-50±21%) (P<0.05). VA was similar amongst conditions. MEP and SP increased and SICI decreased throughout the task while SP was longer for OCCL compared to CYC condition (P<0.05). The results suggest that pain in one leg diminishes contralateral limb exercise tolerance and NMF development and modulate corticospinal inhibition in males. Novelty: Pain in one leg diminished MVC and twitch force decline in the contralateral limb Experimental pain induced by blood flow occlusion may modulation corticospinal inhibition of the neural circuitries innervating the contralateral exercise limb.
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Affiliation(s)
| | | | | | | | | | - Juan M Murias
- University of Calgary, Faculty of Kinesiology, KNB 434, 2500 University Drive NW, Calgary, Alberta, Canada, T2N1N4;
| | - Saied Jalal Aboodarda
- University of Calgary , Faculty of Kinesiology, 2500 University Drive NW, Calgary, Canada, T2N 1N4;
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11
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Ducrocq GP, Blain GM. Relationship between neuromuscular fatigue, muscle activation and the work done above the critical power during severe intensity exercise. Exp Physiol 2022; 107:312-325. [PMID: 35137992 DOI: 10.1113/ep090043] [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: 09/06/2021] [Accepted: 02/02/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does the work done above critical power (W') or muscle activation determine the degree of peripheral fatigue induced by cycling time-trials performed in the severe intensity domain? What is the main finding and its importance? We found that peripheral fatigue increased when power output and muscle activation increased whereas W' did not change between the time-trials. Therefore, no relationship was found between W' and exercise-induced peripheral fatigue such as previously postulated in the literature. In contrast, we found a significant association between EMG amplitude during exercise and exercise-induced reduction in the potentiated quadriceps twitch, suggesting that muscle activation plays a key role in determining peripheral fatigue during severe intensity exercise. ABSTRACT In order to determine the relationship between peripheral fatigue, muscle activation and the total work done above critical power (W'), ten men and four women performed, on separated days, self-paced cycling time-trials of 3, 6, 10, and 15 min. Exercise-induced quadriceps fatigue was quantified using pre- to post-exercise (15 s through 15 min recovery) changes in maximal voluntary contraction peak force (MVC), voluntary activation (VA) and potentiated twitch force (QT). VA was measured using the interpolated twitch technique, and QT was evoked by electrical stimulations of the femoral nerve. Quadriceps muscle activation was determined using the root mean square of surface electromyography of vastus lateralis (VLRMS ), vastus medialis (VMRMS ) and rectus femoris (RFRMS ). Critical power and W' were calculated from the power/duration relationship from the four time-trials. Mean power output and mean VLRMS , VMRMS and RFRMS were greater during shorter compared to longer exercises (P<0.05) whereas no significant between-trials change in W' was found. The magnitude of exercise-induced reductions in QT increased with the increase in power output (P<0.001) and were associated with mean VLRMS and VMRMS (P<0.001, r2 >0.369) but not W' (P>0.150, r2 <0.044). Reduction in VA tended (P = 0.067) to be more pronounced with the lengthening in time-trial duration while no significant between-trials change in MVC were found. Our data suggest that peripheral fatigue is not related to the amount of work done above the critical power but rather to the level of muscle activation during exercise the severe intensity domain. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Guillaume P Ducrocq
- LAMHESS, Université Côte d'Azur, Nice, France.,Faculty of Medicine, Mitochondria, Oxidative Stress and Muscular Protection laboratory (UR 3072), University of Strasbourg, Strasbourg, France.,Faculty of Sport Sciences, European Centre for Education, Research and Innovation in Exercise Physiology (CEERIPE), University of Strasbourg, Strasbourg, France
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12
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Thurston TS, Weavil JC, Hureau TJ, Gifford JR, Georgescu VP, Wan HY, La Salle DT, Richardson RS, Amann M. On the implication of dietary nitrate supplementation for the hemodynamic and fatigue response to cycling exercise. J Appl Physiol (1985) 2021; 131:1691-1700. [PMID: 34672767 PMCID: PMC8714979 DOI: 10.1152/japplphysiol.00400.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/22/2021] [Accepted: 10/14/2021] [Indexed: 11/22/2022] Open
Abstract
This study investigated the impact of dietary nitrate supplementation on peripheral hemodynamics, the development of neuromuscular fatigue, and time to task failure during cycling exercise. Eleven recreationally active male participants (27 ± 5 yr, V̇o2max: 42 ± 2 mL/kg/min) performed two experimental trials following 3 days of either dietary nitrate-rich beetroot juice (4.1 mmol NO3-/day; DNS) or placebo (PLA) supplementation in a blinded, counterbalanced order. Exercise consisted of constant-load cycling at 50, 75, and 100 W (4 min each) and, at ∼80% of peak power output (218 ± 12 W), to task-failure. All participants returned to repeat the shorter of the two trials performed to task failure, but with the opposite supplementation regime (iso-time comparison; ISO). Mean arterial pressure (MAP), leg blood flow (QL; Doppler ultrasound), leg vascular conductance (LVC), and pulmonary gas exchange were continuously assessed during exercise. Locomotor muscle fatigue was determined by the change in pre to postexercise quadriceps twitch-torque (ΔQtw) and voluntary activation (ΔVA; electrical femoral nerve stimulation). Following DNS, plasma [nitrite] (∼670 vs. ∼180 nmol) and [nitrate] (∼775 vs. ∼11 μmol) were significantly elevated compared with PLA. Unlike PLA, DNS lowered both QL and MAP by ∼8% (P < 0.05), but did not alter LVC (P = 0.31). V̇O2 across work rates, as well as cycling time to task-failure (∼7 min) and locomotor muscle fatigue following the ISO-time comparison were not different between the two conditions (ΔQtw ∼42%, ΔVA ∼4%). Thus, despite significant hemodynamic changes, DNS did not alter the development of locomotor muscle fatigue and, ultimately, cycling time to task failure.NEW & NOTEWORTHY This study sought to characterize the impact of dietary nitrate supplementation on the hemodynamic response, locomotor muscle fatigue, and time to task failure during cycling exercise. Although nitrate supplementation lowered mean arterial pressure and exercising leg blood flow, leg vascular conductance and oxygen utilization were unaffected. Despite significant hemodynamic changes, there was no effect of dietary nitrate on neuromuscular fatigue development and, ultimately, cycling time to task failure.
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Affiliation(s)
- Taylor S Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah
| | - Thomas J Hureau
- Department of Medicine, University of Utah, Salt Lake City, Utah
| | - Jayson R Gifford
- Department of Medicine, University of Utah, Salt Lake City, Utah
| | - Vincent P Georgescu
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Hsuan-Yu Wan
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - D Taylor La Salle
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah
- Department of Medicine, University of Utah, Salt Lake City, Utah
| | - Markus Amann
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah
- Department of Medicine, University of Utah, Salt Lake City, Utah
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
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13
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Davies MJ, Lyall GK, Benson AP, Cannon DT, Birch KM, Rossiter HB, Ferguson C. Power Reserve at Intolerance in Ramp-Incremental Exercise Is Dependent on Incrementation Rate. Med Sci Sports Exerc 2021; 53:1606-1614. [PMID: 34261991 DOI: 10.1249/mss.0000000000002645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION The mechanism(s) of exercise intolerance at V˙O2max remain poorly understood. In health, standard ramp-incremental (RI) exercise is limited by fatigue-induced reductions in maximum voluntary cycling power. Whether neuromuscular fatigue also limits exercise when the RI rate is slow and RI peak power at intolerance is lower than standard RI exercise, is unknown. METHODS In twelve healthy participants, maximal voluntary cycling power was measured during a short (~6 s) isokinetic effort at 80 rpm (Piso) at baseline and, using an instantaneous switch from cadence-independent to isokinetic cycling, immediately at the limit of RI exercise with RI rates of 50, 25, and 10 W·min-1 (RI-50, RI-25, and RI-10). Breath-by-breath pulmonary gas exchange was measured throughout. RESULTS Baseline Piso was not different among RI rates (analysis of variance; P > 0.05). Tolerable duration increased with decreasing RI rate (RI-50, 411 ± 58 s vs RI-25, 732 ± 93 s vs RI-10, 1531 ± 288 s; P < 0.05). At intolerance, V˙O2peak was not different among RI rates (analysis of variance; P > 0.05), but RI peak power decreased with RI rate (RI-50, 361 ± 48 W vs RI-25, 323 ± 39 W vs RI-10, 275 ± 38 W; P < 0.05). Piso at intolerance was 346 ± 43 W, 353 ± 45 W, and 392 ± 69 W for RI-50, RI-25, and RI-10, respectively (P < 0.05 for RI-10 vs RI-50 and RI-25). At intolerance, in RI-50 and RI-25, Piso was not different from RI peak power (P > 0.05), thus there was no "power reserve." In RI-10, Piso was greater than RI peak power at intolerance (P < 0.001), that is, there was a "power reserve." CONCLUSIONS In RI-50 and RI-25, the absence of a power reserve suggests the neuromuscular fatigue-induced reduction in Piso coincided with V˙O2max and limited the exercise. In RI-10, the power reserve suggests neuromuscular fatigue was insufficient to limit the exercise, and additional mechanisms contributed to intolerance at V˙O2max.
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Affiliation(s)
- Matthew J Davies
- School of Biomedical Sciences, Faculty of Biological Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UNITED KINGDOM
| | - Gemma K Lyall
- School of Biomedical Sciences, Faculty of Biological Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UNITED KINGDOM
| | - Alan P Benson
- School of Biomedical Sciences, Faculty of Biological Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UNITED KINGDOM
| | - Daniel T Cannon
- School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA
| | - Karen M Birch
- School of Biomedical Sciences, Faculty of Biological Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UNITED KINGDOM
| | | | - Carrie Ferguson
- School of Biomedical Sciences, Faculty of Biological Sciences and Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UNITED KINGDOM
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14
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Martin-Rincon M, Gelabert-Rebato M, Perez-Valera M, Galvan-Alvarez V, Morales-Alamo D, Dorado C, Boushel R, Hallen J, Calbet JAL. Functional reserve and sex differences during exercise to exhaustion revealed by post-exercise ischaemia and repeated supramaximal exercise. J Physiol 2021; 599:3853-3878. [PMID: 34159610 DOI: 10.1113/jp281293] [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: 12/23/2020] [Accepted: 06/17/2021] [Indexed: 01/13/2023] Open
Abstract
KEY POINTS Females have lower fatigability than males during single limb isometric and dynamic contractions, but whether sex-differences exist during high-intensity whole-body exercise remains unknown. This study shows that males and females respond similarly to repeated supramaximal whole-body exercise, and that at task failure a large functional reserve remains in both sexes. Using post-exercise ischaemia with repeated exercise, we have shown that this functional reserve depends on the glycolytic component of substrate-level phosphorylation and is almost identical in both sexes. Metaboreflex activation during post-exercise ischaemia and the O2 debt per kg of active lean mass are also similar in males and females after supramaximal exercise. Females have a greater capacity to extract oxygen during repeated supramaximal exercise and reach lower P ETC O 2 , experiencing a larger drop in brain oxygenation than males, without apparent negative repercussion on performance. Females had no faster recovery of performance after accounting for sex differences in lean mass. ABSTRACT The purpose of this study was to ascertain what mechanisms explain sex differences at task failure and to determine whether males and females have a functional reserve at exhaustion. Exercise performance, cardiorespiratory variables, oxygen deficit, and brain and muscle oxygenation were determined in 18 males and 18 females (21-36 years old) in two sessions consisting of three bouts of constant-power exercise at 120% of V ̇ O 2 max until exhaustion interspaced by 20 s recovery periods. In one of the two sessions, the circulation of both legs was occluded instantaneously (300 mmHg) during the recovery periods. Females had a higher muscle O2 extraction during fatiguing supramaximal exercise than males. Metaboreflex activation, and lean mass-adjusted O2 deficit and debt were similar in males and females. Compared to males, females reached lower P ETC O 2 and brain oxygenation during supramaximal exercise, without apparent negative consequences on performance. After the occlusions, males and females were able to restart exercising at 120% of V ̇ O 2 max , revealing a similar functional reserve, which depends on glycolytic component of substrate-level phosphorylation and its rate of utilization. After ischaemia, muscle O2 extraction was increased, and muscle V ̇ O 2 was similarly reduced in males and females. The physiological response to repeated supramaximal exercise to exhaustion is remarkably similar in males and females when differences in lean mass are considered. Both sexes fatigue with a large functional reserve, which depends on the glycolytic energy supply, yet females have higher oxygen extraction capacity, but reduced P ETC O 2 and brain oxygenation.
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Affiliation(s)
- Marcos Martin-Rincon
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Miriam Gelabert-Rebato
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Mario Perez-Valera
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Victor Galvan-Alvarez
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - David Morales-Alamo
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Cecilia Dorado
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Robert Boushel
- School of Kinesiology, Faculty of Education, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jostein Hallen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Jose A L Calbet
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,School of Kinesiology, Faculty of Education, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
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15
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Ducrocq GP, Hureau TJ, Bøgseth T, Meste O, Blain GM. Recovery from Fatigue after Cycling Time Trials in Elite Endurance Athletes. Med Sci Sports Exerc 2021; 53:904-917. [PMID: 33148973 DOI: 10.1249/mss.0000000000002557] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION We determined the recovery from neuromuscular fatigue in six professional (PRO) and seven moderately trained (MOD) cyclists after repeated cycling time trials of various intensities/durations. METHOD Participants performed two 1-min (1minTT) or two 10-min (10minTT) self-paced cycling time trials with 5 min of recovery in between. Central and peripheral fatigue were quantified via preexercise to postexercise (15-s through 15-min recovery) changes in voluntary activation (VA) and potentiated twitch force. VA was measured using the interpolated twitch technique, and potentiated twitch force was evoked by single (QTsingle) and paired (10-Hz (QT10) and 100-Hz (QT100)) electrical stimulations of the femoral nerve. RESULTS Mean power output was 32%-72% higher during all the time trials and decreased less (-10% vs -13%) from the first to second time trial in PRO compared with MOD (P < 0.05). Conversely, exercise-induced reduction in QTsingle and QT10/QT100 was significantly lower in PRO after every time trial (P < 0.05). Recovery from fatigue from 15 s to 2 min for QTsingle and QT10/QT100 was slower in PRO after every time trial (P < 0.05). In both groups, the reduction in QTsingle was lower after the 10minTTs compared with 1minTTs (P < 0.05). Conversely, VA decreased more after the 10minTTs compared with 1minTTs (P < 0.05). CONCLUSION Our findings showed that excitation-contraction coupling was preserved after exercise in PRO compared with MOD. This likely contributed to the improved performance during repeated cycling time trials of various intensity/duration in PRO, despite a slower rate of recovery in its early phase. Finally, the time course of recovery from neuromuscular fatigue in PRO was dependent on the effects of prolonged low-frequency force depression.
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16
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Kolodziej F, O’Halloran KD. Re-Evaluating the Oxidative Phenotype: Can Endurance Exercise Save the Western World? Antioxidants (Basel) 2021; 10:609. [PMID: 33921022 PMCID: PMC8071436 DOI: 10.3390/antiox10040609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/06/2021] [Accepted: 04/10/2021] [Indexed: 01/16/2023] Open
Abstract
Mitochondria are popularly called the "powerhouses" of the cell. They promote energy metabolism through the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, which in contrast to cytosolic glycolysis are oxygen-dependent and significantly more substrate efficient. That is, mitochondrial metabolism provides substantially more cellular energy currency (ATP) per macronutrient metabolised. Enhancement of mitochondrial density and metabolism are associated with endurance training, which allows for the attainment of high relative VO2 max values. However, the sedentary lifestyle and diet currently predominant in the Western world lead to mitochondrial dysfunction. Underdeveloped mitochondrial metabolism leads to nutrient-induced reducing pressure caused by energy surplus, as reduced nicotinamide adenine dinucleotide (NADH)-mediated high electron flow at rest leads to "electron leak" and a chronic generation of superoxide radicals (O2-). Chronic overload of these reactive oxygen species (ROS) damages cell components such as DNA, cell membranes, and proteins. Counterintuitively, transiently generated ROS during exercise contributes to adaptive reduction-oxidation (REDOX) signalling through the process of cellular hormesis or "oxidative eustress" defined by Helmut Sies. However, the unaccustomed, chronic oxidative stress is central to the leading causes of mortality in the 21st century-metabolic syndrome and the associated cardiovascular comorbidities. The endurance exercise training that improves mitochondrial capacity and the protective antioxidant cellular system emerges as a universal intervention for mitochondrial dysfunction and resultant comorbidities. Furthermore, exercise might also be a solution to prevent ageing-related degenerative diseases, which are caused by impaired mitochondrial recycling. This review aims to break down the metabolic components of exercise and how they translate to athletic versus metabolically diseased phenotypes. We outline a reciprocal relationship between oxidative metabolism and inflammation, as well as hypoxia. We highlight the importance of oxidative stress for metabolic and antioxidant adaptation. We discuss the relevance of lactate as an indicator of critical exercise intensity, and inferring from its relationship with hypoxia, we suggest the most appropriate mode of exercise for the case of a lost oxidative identity in metabolically inflexible patients. Finally, we propose a reciprocal signalling model that establishes a healthy balance between the glycolytic/proliferative and oxidative/prolonged-ageing phenotypes. This model is malleable to adaptation with oxidative stress in exercise but is also susceptible to maladaptation associated with chronic oxidative stress in disease. Furthermore, mutations of components involved in the transcriptional regulatory mechanisms of mitochondrial metabolism may lead to the development of a cancerous phenotype, which progressively presents as one of the main causes of death, alongside the metabolic syndrome.
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Affiliation(s)
- Filip Kolodziej
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, T12 XF62 Cork, Ireland;
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17
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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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18
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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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19
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Amann M, Wan HY, Thurston TS, Georgescu VP, Weavil JC. On the Influence of Group III/IV Muscle Afferent Feedback on Endurance Exercise Performance. Exerc Sport Sci Rev 2020; 48:209-216. [PMID: 32658041 DOI: 10.1249/jes.0000000000000233] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review discusses evidence suggesting that group III/IV muscle afferents affect locomotor performance by influencing neuromuscular fatigue. These neurons regulate the hemodynamic and ventilatory response to exercise and, thus, assure appropriate locomotor muscle O2 delivery, which optimizes peripheral fatigue development and facilitates endurance performance. In terms of central fatigue, group III/IV muscle afferents inhibit motoneuronal output and thereby limit exercise performance.
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Affiliation(s)
| | - Hsuan-Yu Wan
- Department of Anesthesiology, University of Utah
| | - Taylor S Thurston
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT
| | - Vincent P Georgescu
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT
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20
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Weavil JC, Thurston TS, Hureau TJ, Gifford JR, Kithas PA, Broxterman RM, Bledsoe AD, Nativi JN, Richardson RS, Amann M. Heart failure with preserved ejection fraction diminishes peripheral hemodynamics and accelerates exercise-induced neuromuscular fatigue. Am J Physiol Heart Circ Physiol 2020; 320:H338-H351. [PMID: 33164549 DOI: 10.1152/ajpheart.00266.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This study investigated the impact of HFpEF on neuromuscular fatigue and peripheral hemodynamics during small muscle mass exercise not limited by cardiac output. Eight HFpEF patients (NYHA II-III, ejection-fraction: 61 ± 2%) and eight healthy controls performed dynamic knee extension exercise (80% peak workload) to task failure and maximal intermittent quadriceps contractions (8 × 15 s). Controls repeated knee extension at the same absolute intensity as HFpEF. Leg blood flow (QL) was quantified using Doppler ultrasound. Pre/postexercise changes in quadriceps twitch torque (ΔQtw; peripheral fatigue), voluntary activation (ΔVA; central fatigue), and corticospinal excitability were quantified. At the same relative intensity, HFpEF (24 ± 5 W) and controls (42 ± 6 W) had a similar time-to-task failure (∼10 min), ΔQtw (∼50%), and ΔVA (∼6%). This resulted in a greater exercise-induced change in neuromuscular function per unit work in HFpEF, which was significantly correlated with a slower QL response time. Knee extension exercise at the same absolute intensity resulted in an ∼40% lower QL and greater ΔQtw and ΔVA in HFpEF than in controls. Corticospinal excitability remained unaltered during exercise in both groups. Finally, despite a similar ΔVA, ΔQtw was larger in HFpEF versus controls during isometric exercise. In conclusion, HFpEF patients are characterized by a similar development of central and peripheral fatigue as healthy controls when tested at the same relative intensity during exercise not limited by cardiac output. However, HFpEF patients have a greater susceptibility to neuromuscular fatigue during exercise at a given absolute intensity, and this impairs functional capacity. The patients' compromised QL response to exercise likely accounts, at least partly, for the patients' attenuated fatigue resistance.NEW & NOTEWORTHY The susceptibility to neuromuscular fatigue during exercise is substantially exaggerated in individuals with heart failure with a preserved ejection fraction. The faster rate of fatigue development is associated with the compromised peripheral hemodynamic response characterizing these patients during exercise. Given the role of neuromuscular fatigue as a factor limiting exercise, this impairment likely accounts for a significant portion of the exercise intolerance typical for this population.
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Affiliation(s)
- J C Weavil
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - T S Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - T J Hureau
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - J R Gifford
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - P A Kithas
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - R M Broxterman
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - A D Bledsoe
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - J N Nativi
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - R S Richardson
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - M Amann
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.,Department of Anesthesiology, University of Utah, Salt Lake City, Utah
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21
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Pereira HM, de Lima FF, Silva BM, Kohn AF. Sex differences in fatigability after ischemic preconditioning of non-exercising limbs. Biol Sex Differ 2020; 11:59. [PMID: 33109241 PMCID: PMC7590792 DOI: 10.1186/s13293-020-00338-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/18/2020] [Indexed: 12/11/2022] Open
Abstract
Background Ischemic preconditioning (IPC) is suggested to decrease fatigability in some individuals but not others. Sex differences in response to IPC may account for this variability and few studies systematically investigated the effects of IPC in men and women. The goal of this study was to determine if time to task failure, perception of pain, and neuromuscular mechanisms of fatigability were altered by IPC in men and women. Methods Ten women (29 ± 5 years old) and 10 men (28 ± 6 years old) performed isometric contractions with the plantar flexor muscles of the dominant leg at 20% of maximal voluntary contraction until task failure. We used a repeated measures design where each individual performed 3 randomized and counterbalanced test sessions: (A) IPC session, cuff inflation and deflation (5 min each repeated 3 times) performed before the exercise by inflating cuffs to the non-dominant leg and arm; (B) sham session, cuffs were inflated for a short period (1 min); and (C) control session, no cuffs were involved. Results Compared with control, IPC increased time to task failure in men (mean difference, 5 min; confidence interval (CI) of mean difference, 2.2; 7.8 min; P = 0.01) but not women (mean difference, − 0.6 min; CI of mean difference, − 3.5; 2.4 min; P = 0.51). In men, but not women, the IPC-induced increase in time to task failure was associated with lower response to pressure pain (r = − 0.79). IPC further exposed sex differences in arterial pressure during fatiguing contractions (session × sex: P < 0.05). Voluntary activation, estimated with the twitch interpolation technique, and presynaptic inhibition of leg Ia afferents were not altered after IPC for men and women. The tested variables were not altered with sham. Conclusions The ergogenic effect of IPC on time to task failure was observed only in men and it was associated with reductions in the perception of pain. This pilot data suggest the previously reported inter-individual variability in exercise-induced fatigability after IPC could be a consequence of the sex and individual response to pain.
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Affiliation(s)
- Hugo M Pereira
- Department of Health and Exercise Science, University of Oklahoma, 1401 Asp Ave, Norman, OK, 73019, USA.
| | - Felipe F de Lima
- Biomedical Engineering Laboratory/EPUSP, University of São Paulo, São Paulo, SP, Brazil
| | - Bruno M Silva
- Department of Physiology, Federal University of São Paulo, São Paulo, SP, Brazil
| | - André F Kohn
- Biomedical Engineering Laboratory/EPUSP, University of São Paulo, São Paulo, SP, Brazil
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22
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Teixeira AL, Fernandes IA, Vianna LC. Cardiovascular Control During Exercise: The Connectivity of Skeletal Muscle Afferents to the Brain. Exerc Sport Sci Rev 2020; 48:83-91. [PMID: 32000180 DOI: 10.1249/jes.0000000000000218] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The exercise pressor reflex (EPR) is engaged upon the activation of group III/IV skeletal muscle afferents and is one of the principal mediators of cardiovascular responses to exercise. This review explores the hypothesis that afferent signals from EPR communicate via GABAergic contacts within the brain stem to evoke parasympathetic withdrawal and sympathoexcitation to increase cardiac output, peripheral resistance, and blood pressure during exercise.
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Affiliation(s)
- André L Teixeira
- NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, DF, Brazil
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23
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Fulton TJ, Baranauskas MN, Paris HL, Koceja DM, Mickleborough TD, Chapman RF. Respiratory Muscle Fatigue Alters Cycling Performance and Locomotor Muscle Fatigue. Med Sci Sports Exerc 2020; 52:2380-2389. [PMID: 33064411 DOI: 10.1249/mss.0000000000002399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to determine if preexisting respiratory muscle fatigue (RMF) alters motoneuronal output, locomotor muscle fatigue, and cycling performance. METHODS Eight trained male cyclists performed 5-km cycling time trials after a resistive breathing task that induced RMF and under control conditions (CON). Motoneuronal output was estimated using vastus lateralis surface electromyography, and locomotor muscle fatigue was quantified as the change in potentiated quadriceps twitch force from preexercise to postexercise. RESULTS Time to complete the time trial was 1.9% ± 0.9% longer in RMF compared with CON (P < 0.001). Estimated motoneuronal output was lower in RMF compared with CON during 1 km (45% ± 11% vs 53% ± 13%, P = 0.004) and 2 km (45% ± 14% vs 51% ± 14%, P = 0.008), but was not different thereafter. Ventilation was lower in RMF compared with CON during 1 km (114 ± 19 vs 135 ± 24 L·min, P = 0.003) and 2 km (136 ± 23 vs 152 ± 31 L·min, P = 0.009); however, ratings of dyspnea were similar. After the 5-km time trial, locomotor muscle fatigue was attenuated in RMF compared with CON (-22% ± 6%, vs -28% ± 7%, P = 0.02). CONCLUSIONS Alterations to dyspnea for a given ventilation seem to have constrained power output during cycling exercise, thereby limiting the development of locomotor muscle fatigue. These findings indicate that the respiratory system is an integral component in a global feedback loop that regulates exercise performance and the development of locomotor muscle fatigue.
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Affiliation(s)
- Timothy J Fulton
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
| | - Marissa N Baranauskas
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
| | - Hunter L Paris
- Department of Sports Medicine, Pepperdine University, Malibu, CA
| | - David M Koceja
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
| | - Timothy D Mickleborough
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
| | - Robert F Chapman
- Department of Kinesiology, School of Public Health-Bloomington, Indiana University, Bloomington, IN
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24
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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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25
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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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26
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Dempsey JA, La Gerche A, Hull JH. Is the healthy respiratory system built just right, overbuilt, or underbuilt to meet the demands imposed by exercise? J Appl Physiol (1985) 2020; 129:1235-1256. [PMID: 32790594 DOI: 10.1152/japplphysiol.00444.2020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In the healthy, untrained young adult, a case is made for a respiratory system (airways, pulmonary vasculature, lung parenchyma, respiratory muscles, and neural ventilatory control system) that is near ideally designed to ensure a highly efficient, homeostatic response to exercise of varying intensities and durations. Our aim was then to consider circumstances in which the intra/extrathoracic airways, pulmonary vasculature, respiratory muscles, and/or blood-gas distribution are underbuilt or inadequately regulated relative to the demands imposed by the cardiovascular system. In these instances, the respiratory system presents a significant limitation to O2 transport and contributes to the occurrence of locomotor muscle fatigue, inhibition of central locomotor output, and exercise performance. Most prominent in these examples of an "underbuilt" respiratory system are highly trained endurance athletes, with additional influences of sex, aging, hypoxic environments, and the highly inbred equine. We summarize by evaluating the relative influences of these respiratory system limitations on exercise performance and their impact on pathophysiology and provide recommendations for future investigation.
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Affiliation(s)
- Jerome A Dempsey
- John Robert Sutton Professor of Population Health Sciences, John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Andre La Gerche
- Clinical Research Domain, Baker Heart and Diabetes Institute, Melbourne, Australia.,National Center for Sports Cardiology, St. Vincent's Hospital, Melbourne, Fitzroy, Australia
| | - James H Hull
- Department of Respiratory Medicine, Royal Brompton Hospital, London, United Kingdom.,Institute of Sport, Exercise and Health (ISEH), University College London, United Kingdom
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27
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Smith SGVS, Power GA, Bent LR. Foot sole cutaneous stimulation mitigates neuromuscular fatigue during a sustained plantar flexor isometric task. J Appl Physiol (1985) 2020; 129:325-334. [PMID: 32584665 DOI: 10.1152/japplphysiol.00157.2020] [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] [Indexed: 01/23/2023] Open
Abstract
Neuromuscular fatigue impairs motor coordination, movement stability, and proprioception, which further decreases performance. A neuromechanical coupling exists between foot sole cutaneous mechanoreceptors and motoneurons of the lower limb, however, the contribution of skin sensory input on muscle fatigue remains unclear. The purpose of this study was to determine if the presence of cutaneous stimulation could mitigate the effect of fatigue of the plantar flexor muscles during a sustained isometric task at 30% maximal voluntary contraction (MVC). Participants (N = 16, age 24.1 ± 2.6 yr) underwent a 30% isometric plantar flexor fatiguing task in a seated position with hip, knee, and ankle angle at 80°, 100°, and 90°, respectively, with intermittent MVCs until task failure. Failure was defined as when the participant could no longer maintain 30% MVC for a minimum of two seconds. Throughout the protocol, electrical stimulation was applied to either the right heel, right metatarsals, or no stimulation. A subset of participants (N = 6) underwent an additional condition with electrical stimulation applied to the left arm. MVCs were also conducted intermittently throughout recovery for 30 min. Foot sole cutaneous stimulation mitigated fatigue, as demonstrated by an ~15% increased time to task failure (TTF) compared with the control condition. When normalized to TTF, MVC torque amplitude was not different at each time epoch, which indicated that each %MVC was maintained longer into the fatigue task during the heel and metatarsal stimulation conditions However, there was no significant effect of cutaneous stimulation on recovery. The results indicate that cutaneous stimulation may serve as a feasible means to mitigate fatigue.NEW & NOTEWORTHY Cutaneous coupling with lower limb motor neurons has long been known. We set out to establish whether this pathway could serve a purpose other than muscular modulation during standing and walking. We found that during a submaximal contraction of the plantar flexor muscles, the addition of intermittent cutaneous stimulation to the skin of the foot sole resulted in an increase in time to task failure by 15%, which was over a minute longer in duration. We conclude that skin stimulation may serve as a mechanism to mitigate fatigue.
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Affiliation(s)
- Simone G V S Smith
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Leah R Bent
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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28
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Grotle AK, Macefield VG, Farquhar WB, O'Leary DS, Stone AJ. Recent advances in exercise pressor reflex function in health and disease. Auton Neurosci 2020; 228:102698. [PMID: 32861944 DOI: 10.1016/j.autneu.2020.102698] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 01/11/2023]
Abstract
Autonomic alterations at the onset of exercise are critical to redistribute cardiac output towards the contracting muscles while preventing a fall in arterial pressure due to excessive vasodilation within the contracting muscles. Neural mechanisms responsible for these adjustments include central command, the exercise pressor reflex, and arterial and cardiopulmonary baroreflexes. The exercise pressor reflex evokes reflex increases in sympathetic activity to the heart and systemic vessels and decreases in parasympathetic activity to the heart, which increases blood pressure (BP), heart rate, and total peripheral resistance through vasoconstriction of systemic vessels. In this review, we discuss recent advancements in our understanding of exercise pressor reflex function in health and disease. Specifically, we discuss emerging evidence suggesting that sympathetic vasoconstrictor drive to the contracting and non-contracting skeletal muscle is differentially controlled by central command and the metaboreflex in healthy conditions. Further, we discuss evidence from animal and human studies showing that cardiovascular diseases, including hypertension, diabetes, and heart failure, lead to an altered exercise pressor reflex function. We also provide an update on the mechanisms thought to underlie this altered exercise pressor reflex function in each of these diseases. Although these mechanisms are complex, multifactorial, and dependent on the etiology of the disease, there is a clear consensus that several mechanisms are involved. Ultimately, approaches targeting these mechanisms are clinically significant as they provide alternative therapeutic strategies to prevent adverse cardiovascular events while also reducing symptoms of exercise intolerance.
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Affiliation(s)
- Ann-Katrin Grotle
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States of America
| | | | - William B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States of America
| | - Donal S O'Leary
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Audrey J Stone
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States of America.
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29
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Muscle pain induced by hypertonic saline in the knee extensors decreases single-limb isometric time to task failure. Eur J Appl Physiol 2020; 120:2047-2058. [PMID: 32613451 PMCID: PMC7419372 DOI: 10.1007/s00421-020-04425-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/19/2020] [Indexed: 12/02/2022]
Abstract
Purpose Increased nociceptive activity and the experience of exercise-induced pain (EIP) may contribute to fatigue during endurance exercise. To investigate this, a pain model that produces pain similar to EIP and decouples its relationship to exercise intensity is required. This study (1) compared the quality of pain caused by a hypertonic saline injection into the vastus lateralis in resting and exercise conditions, and (2) investigated whether this pain contributes to changes in time to task failure. Methods On separate days, 18 participants completed a time to task failure at 20% maximal voluntary torque (MVT), a resting hypertonic saline intramuscular injection, and in a further three visits a time to task failure at 10% MVT following injection of isotonic saline, hypertonic saline or a control (no injection). Results In a subset of eligible participants (n = 12), the hypertonic saline combined with 10% MVT produced a qualitative experience of pain (assessed by the McGill Pain Questionnaire) that felt similar to EIP. 10% MVT with hypertonic saline significantly elevated pain intensity in the first 20% of the time to task failure and caused a significantly (P < 0.05) shorter time to task failure (448 ± 240 s) compared with the isotonic saline (605 ± 285 s) and control (514 ± 197 s) conditions. Conclusion These findings demonstrate that hypertonic saline increases the intensity of pain during exercise, which results in a faster occurrence of exercise-induced fatigue. These results provide important evidence supporting pain as a limiting factor in endurance performance.
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30
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Khataei T, Harding AMS, Janahmadi M, El-Geneidy M, Agha-Alinejad H, Rajabi H, Snyder PM, Sluka KA, Benson CJ. ASICs are required for immediate exercise-induced muscle pain and are downregulated in sensory neurons by exercise training. J Appl Physiol (1985) 2020; 129:17-26. [PMID: 32463731 DOI: 10.1152/japplphysiol.00033.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exercise training is an effective therapy for many pain-related conditions, and trained athletes have lower pain perception compared with unconditioned people. Some painful conditions, including strenuous exercise, are associated with elevated levels of protons, metabolites, and inflammatory factors, which may activate receptors and/or ion channels, including acid-sensing ion channels (ASICs), on nociceptive sensory neurons. We hypothesized that ASICs are required for immediate exercise-induced muscle pain (IEIP) and that exercise training diminishes IEIP by modulating ASICs within muscle afferents. We found high-intensity interval training (HIIT) reduced IEIP in C57BL/6 mice and diminished ASIC mRNA levels in lumber dorsal root ganglia, and this downregulation of ASICs correlated with improved exercise capacity. Additionally, we found that ASIC3 -/- mice did not develop IEIP; however, the exercise capacity of ASIC3 -/- was similar to wild-type mice. These results suggest that ASICs are required for IEIP and that diminishment of IEIP after exercise training correlates with downregulation of ASICs in sensory neurons.NEW & NOTEWORTHY Exercise performance can be limited by the sensations of muscle fatigue and pain transmitted by muscle afferents. It has been proposed that exercise training abrogates these negative feedback signals. We found that acid-sensing ion channels (ASICs) are required for immediate exercise-induced muscle pain (IEIP). Moreover, exercise training prevented IEIP and was correlated with downregulation of ASICs in sensory neurons.
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Affiliation(s)
- Tahsin Khataei
- Department of Exercise Physiology, Tarbiat Modares University, Tehran, Iran.,Department of Internal Medicine, University of Iowa, Roy J. and Lucile A. Carver College of Medicine, Iowa City, Iowa.,Iowa City Veterans Affairs Healthcare System, Iowa City, Iowa
| | - Anne Marie S Harding
- Department of Internal Medicine, University of Iowa, Roy J. and Lucile A. Carver College of Medicine, Iowa City, Iowa.,Iowa City Veterans Affairs Healthcare System, Iowa City, Iowa
| | - Mahyar Janahmadi
- Department of Physiology and Neuroscience Research Center, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maram El-Geneidy
- Department of Internal Medicine, University of Iowa, Roy J. and Lucile A. Carver College of Medicine, Iowa City, Iowa.,Iowa City Veterans Affairs Healthcare System, Iowa City, Iowa
| | | | - Hamid Rajabi
- Department of Exercise Physiology, Kharazmi University, Tehran, Iran
| | - Peter M Snyder
- Department of Internal Medicine, University of Iowa, Roy J. and Lucile A. Carver College of Medicine, Iowa City, Iowa.,Iowa City Veterans Affairs Healthcare System, Iowa City, Iowa
| | - Kathleen A Sluka
- Department of Physical Therapy and Rehabilitation Science, The University of Iowa, Iowa City, Iowa.,Neuroscience Institute, The University of Iowa, Iowa City, Iowa
| | - Christopher J Benson
- Department of Internal Medicine, University of Iowa, Roy J. and Lucile A. Carver College of Medicine, Iowa City, Iowa.,Iowa City Veterans Affairs Healthcare System, Iowa City, Iowa.,Department of Pharmacology, University of Iowa, Roy J. and Lucile A. Carver College of Medicine, Iowa City, Iowa
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31
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Korzeniewski B, Rossiter HB. Exceeding a "critical" muscle P i: implications for [Formula: see text] and metabolite slow components, muscle fatigue and the power-duration relationship. Eur J Appl Physiol 2020; 120:1609-1619. [PMID: 32435984 DOI: 10.1007/s00421-020-04388-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/02/2020] [Indexed: 12/21/2022]
Abstract
PURPOSE The consequences of the assumption that the additional ATP usage, underlying the slow component of oxygen consumption ([Formula: see text]) and metabolite on-kinetics, starts when cytosolic inorganic phosphate (Pi) exceeds a certain "critical" Pi concentration, and muscle work terminates because of fatigue when Pi exceeds a certain, higher, "peak" Pi concentration are investigated. METHODS A previously developed computer model of the myocyte bioenergetic system is used. RESULTS Simulated time courses of muscle [Formula: see text], cytosolic ADP, pH, PCr and Pi at various ATP usage activities agreed well with experimental data. Computer simulations resulted in a hyperbolic power-duration relationship, with critical power (CP) as an asymptote. CP was increased, and phase II [Formula: see text] on-kinetics was accelerated, by progressive increase in oxygen tension (hyperoxia). CONCLUSIONS Pi is a major factor responsible for the slow component of the [Formula: see text] and metabolite on-kinetics, fatigue-related muscle work termination and hyperbolic power-duration relationship. The successful generation of experimental system properties suggests that the additional ATP usage, underlying the slow component, indeed starts when cytosolic Pi exceeds a "critical" Pi concentration, and muscle work terminates when Pi exceeds a "peak" Pi concentration. The contribution of other factors, such as cytosolic acidification, or glycogen depletion and central fatigue should not be excluded. Thus, a detailed quantitative unifying mechanism underlying various phenomena related to skeletal muscle fatigue and exercise tolerance is offered that was absent in the literature. This mechanism is driven by reciprocal stimulation of Pi increase and additional ATP usage when "critical" Pi is exceeded.
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Affiliation(s)
| | - Harry B Rossiter
- Rehabilitation Clinical Trials Center, Division of Pulmonary and Critical Care Physiology and Medicine, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA.,Faculty of Biological Sciences, University of Leeds, Leeds, UK
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