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Does Oxygen Uptake Before Physical Exercise Affect Tear Osmolarity? J Hum Kinet 2020; 73:297-304. [PMID: 32774560 PMCID: PMC7386152 DOI: 10.2478/hukin-2019-0118] [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] [Indexed: 11/20/2022] Open
Abstract
Recently, it has been reported that tear osmolarity (Tosm) is correlated with plasma osmolarity and will increase during exertion. We aimed to assess whether inhaling oxygen-enriched air between exercises could significantly change the Tosm value. Thirty men aged 24.9 years were included in the study. A cycloergometer was used to perform the exercise protocol. We recorded the participants’ Tosm (mOsm/L), heart rate (HR, beats/minute), oxygen saturation, and blood pressure values. After the first exhaustive exercise (T1), participants inhaled oxygen in the experimental group and a placebo in the control group. After the second exercise (T2), another set of measurements was obtained. The Tosm value before exercise was 297.4 ± 1.21 and 296.53 ± 1.11 mOsm/L (p = 0.61718) and the HR was 72.6 ± 2.59 and 73 ± 2.59 beats/minute (p = 0.39949) in the study and the control group, respectively. At T1, Tosm was 303.67 ± 1.25 and 302.2 ± 1.25 mOsm/L (p = 0.41286) and the HR reached 178.04 ± 2.60 and 176.4 ± 2.60 beats/minute (p = 0.65832), respectively. At T2, Tosm in the study group reached 305.73 ± 0.86 mOsm/L (correlation with the use of oxygen: r = −0.3818), and in the control group, it was 308.4 ± 0.86 mOsm/L (p = 0.0373), while the HR reached 172.20 ± 2.53 beats/minute in the study group and 178.2 ± 2.53 beats/minute in the control group (p = 0.057). It was concluded that inhaling oxygen before and after exercise could increase the rate of recovery after exhaustive exercise.
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Botonis PG, Miliotis PG, Kounalakis SN, Koskolou MD, Geladas ND. Thermoregulatory and cardiovasculareffects of capsaicin application on human skin during dynamic exercise to temperate and warm conditions. Physiol Rep 2019; 7:e14325. [PMID: 31883232 PMCID: PMC6934878 DOI: 10.14814/phy2.14325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Thermoregulatory and cardiovascular responses during cycling in temperate and warm environments without and with application of capsaicin on the skin were investigated. We hypothesized that regardless of environmental temperature, capsaicin application would activate heat loss mechanisms attenuating exercise‐induced rectal temperature (Tre) and blood pressure increase. Eight males cycled at 55% of their maximal aerobic power so long as to reach 38.2°C Tre at 20.8 ± 1.0°C and at 30.6 ± 1.1°C ambient temperatures twice: without (NCA) and with (CA) application of capsaicin patches (12 × 18 cm, 4.8 mg). Patches were applied on pectoralis major, trapezius and vastus lateralis muscles. Thermoregulatory (Tre, proximal‐distal skin temperature gradient, sweating rate), cardiovascular variables and oxygen uptake were continuously recorded. In both ambient conditions, during the first 14 min of exercise, the local vasoconstrictive tone as a function of the relative change in Tre was lower in CA than NCA (p < .05, d = 0.84–1.15). Further, sweating rate was higher and occurred at a lower Tre increase in CA compared to NCA (p = .03, d = 0.6) resulting in extended time to reach 38.2°C Tre (p = .03, d = 0.9). Moreover, oxygen consumption was higher in CA than in NCA (p < .001, d = 0.8). Mean arterial pressure was lower during cycling in warm compared to temperate environment, but was unaffected by capsaicin. We conclude that activation of thermal sensors by capsaicin results in lower Tre rise during exercise, which is mediated through greater skin vasodilation along with higher rate and earlier onset of sweating. Nonetheless, capsaicin application has no extra effect on exercise cardiovascular responses.
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Affiliation(s)
- Petros G Botonis
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis G Miliotis
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Stylianos N Kounalakis
- Faculty of Physical and Cultural Education, Evelpidon Hellenic Army Academy, Vari, Greece
| | - Maria D Koskolou
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Nickos D Geladas
- Section of Sport Medicine and Biology of Exercise, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
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Lu CQ, Xu W, Zeng CH, Ge LY, Wang YC, Meng XP, Yu Q, Wu D, Ju S. Altered amplitude of low-frequency fluctuation in basal ganglia correlates to pulmonary ventilation function in COPD patients: A resting-state fMRI study. Brain Behav 2019; 9:e01336. [PMID: 31140760 PMCID: PMC6625472 DOI: 10.1002/brb3.1336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/01/2019] [Accepted: 05/06/2019] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION Patients under chronic obstructive pulmonary disease (COPD) has been reported to be associated with a higher prevalence of cognitive impairment (CI). However, it is still largely unknown whether the aberrant resting-state spontaneous neuronal activity pattern reflected by the amplitude of low-frequency fluctuation (ALFF) analysis will be associated with the CI in COPD patients. MATERIALS A total of 28 COPD patients and 26 healthy controls were enrolled in this study. Of all the subjects, structural and functional MRI data, spirometry tests performance and neuropsychological assessments of different cognitive domains were collected. Voxel-based two-sample t tests were used to detect brain regions showing differences in the ALFF value between COPD patients and healthy controls. An additional fMRI runs with supplementary oxygen delivery were employed to explore the impact of elevated partial pressure of oxygen (PaO2 ) or moderate hyperoxia on ALFF in COPD patients and healthy controls respectively. RESULTS More extensive white matter lesion was detected in COPD patients. COPD patients exhibit decreased ALFF value in bilateral basal ganglia areas and right thalamus, and aberrant ALFF value is correlated with PaO2 and pulmonary ventilation function (FEV1%pred). COPD patients performed worse in the Digit Span Test (reverse), Digit Symbol Substitution Test, Trail-making test (A and B) than controls. After supplementary oxygen inhalation, the ALFF value of basal ganglia and right thalamus significantly increased in the controls, but not in the COPD patients. CONCLUSIONS COPD patients mainly exhibit impaired executive function but not long-term memory in cognitive function assessment. Aberrant ALFF alteration in the deep brain may be directly related to lower PaO2 in COPD patients.
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Affiliation(s)
- Chun-Qiang Lu
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Weiwei Xu
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Chu-Hui Zeng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Lu-Yao Ge
- Department of Respirology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Yuan-Cheng Wang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Xiang-Pan Meng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Qian Yu
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Di Wu
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Shenghong Ju
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
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Schoffelen PFM, den Hoed M, van Breda E, Plasqui G. Test-retest variability of VO 2max using total-capture indirect calorimetry reveals linear relationship of VO 2 and Power. Scand J Med Sci Sports 2018; 29:213-222. [PMID: 30341979 PMCID: PMC7379248 DOI: 10.1111/sms.13324] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 03/07/2018] [Accepted: 10/12/2018] [Indexed: 12/20/2022]
Abstract
This study aimed to analyze the intra‐individual variation in VO2max of human subjects using total‐capture and free‐flow indirect calorimetry. Twenty‐seven men (27 ± 5 year; VO2max 49‐79 mL•kg−1•min−1) performed two maximal exertion tests (CPETs) on a cycle ergometer, separated by a 7 ± 2 day interval. VO2 and VCO2 were assessed using an indirect calorimeter (Omnical) with total capture of exhalation in a free‐flow airstream. Thirteen subjects performed a third maximal exertion test using a breath‐by‐breath calorimeter (Oxycon Pro). On‐site validation was deemed a requirement. For the Omnical, the mean within‐subject CV for VO2max was 1.2 ± 0.9% (0.0%‐4.4%) and for ergometer workload Pmax 1.3 ± 1.3% (0%‐4.6%). VO2max values with the Oxycon Pro were significantly lower in comparison with Omnical (P < 0.001; t test) with mean 3570 vs 4061 and difference SD 361 mL•min−1. Validation results for the Omnical with methanol combustion were −0.05 ± 0.70% (mean ± SD; n = 31) at the 225 mL•min−1 VO2 level and −0.23 ± 0.80% (n = 31) at the 150 mL•min−1 VCO2 level. Results using gas infusion were 0.04 ± 0.75% (n = 34) and −0.99 ± 1.05% (n = 24) over the respective 500‐6000 mL•min−1 VO2 and VCO2 ranges. Validation results for the Oxycon Pro in breath‐by‐breath mode were ‐ 2.2 ± 1.6% (n = 12) for VO2 and 5.7 ± 3.3% (n = 12) for VCO2 over the 1000‐4000 mL•min−1 range. On a Visual analog scale, participants reported improved breathing using the free‐flow indirect calorimetry (score 7.6 ± 1.2 vs 5.1 ± 2.7, P = 0.008). We conclude that total capturing free‐flow indirect calorimetry is suitable for measuring VO2 even with the highest range. VO2max was linear with the incline in Pmax over the full range.
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Affiliation(s)
- Paul F M Schoffelen
- Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands.,Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marcel den Hoed
- Department of Immunology, Genetics and Pathology and SciLifeLab, Uppsala University, Uppsala, Sweden
| | - Eric van Breda
- Faculty of Medicine and Health Sciences, Department of Rehabilitation Sciences and Physiotherapy/MOVANT, University of Antwerp, Antwerp, Belgium
| | - Guy Plasqui
- Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
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Marwood S, Constantin-Teodosiu D, Casey E, Whyte M, Boobis L, Bowtell J. No acetyl group deficit is evident at the onset of exercise at 90% of maximal oxygen uptake in humans. J Sports Sci 2015; 28:267-79. [PMID: 20087812 DOI: 10.1080/02640410903440884] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The existence of an acetyl group deficit at or above 90% of maximal oxygen uptake (VO(2max)) has proved controversial, with contradictory results likely relating to limitations in previous research. The purpose of the present study was to determine whether the "acetyl group deficit" occurs at the start of exercise at 90%VO(2max) in a well-controlled study. Eight male participants (age: 33.6 +/- 2.0 years; VO(2max): 3.60 +/- 0.21 litres . min(-1)) completed two exercise bouts at 90%VO(2max) for 3 min following either 30 min of saline (control) or dichloroacetate (50 mg . kg(-1) body mass) infusion, ending 15 min before exercise. Muscle biopsies were obtained immediately before and after exercise while continuous non-invasive measures of pulmonary oxygen uptake and muscle deoxygenation were made. Muscle pyruvate dehydrogenase activity was significantly higher before exercise following dichloroacetate infusion (control: 2.67 +/- 0.98 vs. dichloroacetate: 17.9 +/- 1.1 mmol acetyl-CoA . min(-1) . mg(-1) protein, P = 0.01) and resulted in higher pre- and post-exercise muscle acetylcarnitine (pre-exercise control: 3.3 +/- 0.95 vs. pre-exercise dichloroacetate: 8.0 +/- 0.88 vs. post-exercise control: 11.9 +/- 1.1 vs. post-exercise dichloroacetate: 17.2 +/- 1.1 mmol . kg(-1) dry muscle, P < 0.05). However, substrate-level phosphorylation (control: 125 +/- 20 vs. dichloroacetate: 113 +/- 13 mmol adenosine triphosphate . kg(-1) dry muscle) and VO(2) kinetics (control: 19.2 +/- 2.2 vs. dichloroacetate: 22.8 +/- 2.5 s), were unaltered. Furthermore, dichloroacetate infusion blunted the slow component of VO(2) and muscle deoxygenation and slowed muscle deoxygenation kinetics, possibly by enhancing oxygen delivery during exercise. These data support the hypothesis that the "acetyl group deficit" does not occur at or above 90%VO(2max).
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Affiliation(s)
- Simon Marwood
- Health and Biology, Liverpool Hope University, Liverpool
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Garcia-Tabar I, Eclache JP, Aramendi JF, Gorostiaga EM. Gas analyzer's drift leads to systematic error in maximal oxygen uptake and maximal respiratory exchange ratio determination. Front Physiol 2015; 6:308. [PMID: 26578980 PMCID: PMC4626835 DOI: 10.3389/fphys.2015.00308] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/13/2015] [Indexed: 01/07/2023] Open
Abstract
The aim was to examine the drift in the measurements of fractional concentration of oxygen (FO2) and carbon dioxide (FCO2) of a Nafion-using metabolic cart during incremental maximal exercise in 18 young and 12 elderly males, and to propose a way in which the drift can be corrected. The drift was verified by comparing the pre-test calibration values with the immediate post-test verification values of the calibration gases. The system demonstrated an average downscale drift (P < 0.001) in FO2 and FCO2 of -0.18% and -0.05%, respectively. Compared with measured values, corrected average maximal oxygen uptakevalues were 5-6% lower (P < 0.001) whereas corrected maximal respiratory exchange ratio values were 8-9% higher (P < 0.001). The drift was not due to an electronic instability in the analyzers because it was reverted after 20 min of recovery from the end of the exercise. The drift may be related to an incomplete removal of water vapor from the expired gas during transit through the Nafion conducting tube. These data demonstrate the importance of checking FO2 and FCO2 values by regular pre-test calibrations and post-test verifications, and also the importance of correcting a possible shift immediately after exercise.
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Affiliation(s)
- Ibai Garcia-Tabar
- Studies, Research and Sports Medicine Center, Government of Navarre Pamplona, Spain
| | - Jean P Eclache
- Laboratory of Performance, Sport-Occupational Activities-Biology-Association Lyon-Chassieu, France
| | - José F Aramendi
- Studies, Research and Sports Medicine Center, Government of Navarre Pamplona, Spain
| | - Esteban M Gorostiaga
- Studies, Research and Sports Medicine Center, Government of Navarre Pamplona, Spain
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7
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Stensrud T, Stang J, Thorsen E, Bråten V. Exhaled nitric oxide concentration in the period of 60 min after submaximal exercise in the cold. Clin Physiol Funct Imaging 2014; 36:85-91. [PMID: 25302764 DOI: 10.1111/cpf.12196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 09/08/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Fractional expired nitric oxide (FENO ) is decreased after exercise. The effect of exercise in the cold upon FENO is unknown. PURPOSE To examine changes in FENO after a short, high intensive exercise test in a cold and in a temperate environment. METHODS Twenty healthy well-trained subjects (eight females) aged 18-28 years performed an 8-min exercise test at 18°C (SD = 1.0) and -10°C (SD = 1.2) ambient temperature. The tests were performed in a climate chamber in random order. The workload corresponded to 90-95% of peak heart rate (HRpeak ) during the last 4 min. FENO was measured offline. Exhaled gas was sampled in Mylar(®) bags using a collector kit with a flow restrictor and analysed within 2 h. FENO was measured before exercise and repeatedly during the first hour after. ANOVA for repeated measures was used to compare differences in FENO after exercise between environments. RESULTS There was no difference in baseline FENO . A significant difference in FENO between environments was found after warm-up and from 20 to 30 min after exercise, with FENO being lower after exercise in the cold (P<0.05). The maximal reduction in FENO was seen 5 min after exercise and was not different between environments. CONCLUSION Recovery of FENO was slower after exercising in -10°C compared with 18°C.
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Affiliation(s)
- Trine Stensrud
- Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway
| | - Julie Stang
- Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway
| | - Einar Thorsen
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway
| | - Veslemøy Bråten
- Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway
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Prieur F, Benoît H. Rôle de l’apport d’O2 dans la limitation de la consommation maximale d’oxygène. Sci Sports 2011. [DOI: 10.1016/j.scispo.2010.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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Schrack JA, Simonsick EM, Ferrucci L. Comparison of the Cosmed K4b(2) portable metabolic system in measuring steady-state walking energy expenditure. PLoS One 2010; 5:e9292. [PMID: 20174583 PMCID: PMC2823789 DOI: 10.1371/journal.pone.0009292] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Accepted: 12/19/2009] [Indexed: 11/24/2022] Open
Abstract
Background and Aims Recent introduction of the Cosmed K4b2 portable metabolic analyzer allows measurement of oxygen consumption outside of a laboratory setting in more typical clinical or household environments and thus may be used to obtain information on the metabolic costs of specific daily life activities. The purpose of this study was to assess the accuracy of the Cosmed K4b2 portable metabolic analyzer against a traditional, stationary gas exchange system (the Medgraphics D-Series) during steady-state, submaximal walking exercise. Methods Nineteen men and women (9 women, 10 men) with an average age of 39.8 years (±13.8) completed two 400 meter walk tests using the two systems at a constant, self-selected pace on a treadmill. Average oxygen consumption (VO2) and carbon dioxide production (VCO2) from each walk were compared. Results Intraclass Correlation Coefficient (ICC) and Pearson correlation coefficients between the two systems for weight indexed VO2 (ml/kg/min), total VO2 (ml/min), and VCO2 (ml/min) ranged from 0.93 to 0.97. Comparison of the average values obtained using the Cosmed K4b2 and Medgraphics systems using paired t-tests indicate no significant difference for VO2 (ml/kg/min) overall (p = 0.25), or when stratified by sex (p = 0.21 women, p = 0.69 men). The mean difference between analyzers was – 0.296 ml/kg/min (±0.26). Results were not significantly different for VO2 (ml/min) or VCO2 (ml/min) within the study population (p = 0.16 and p = 0.08, respectively), or when stratified by sex (VO2: p = 0.51 women, p = 0.16 men; VCO2: p = .11 women, p = 0.53 men). Conclusion The Cosmed K4b2 portable metabolic analyzer provides measures of VO2 and VCO2 during steady-state, submaximal exercise similar to a traditional, stationary gas exchange system.
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Affiliation(s)
- Jennifer A Schrack
- Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America.
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Marwood S, Bowtell J. No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise. J Sports Sci 2009; 26:1081-90. [PMID: 18608833 DOI: 10.1080/02640410801930200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g kg body mass(-1) of glutamine in 5 ml kg body mass(-1) placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO(2) = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake (VO(2max)) immediately before completing a brief high-intensity time-trial (approximately 4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (DeltaVO(2max), P = 0.02) and exercise performance (control: 243 s, s(x) = 7; glutamine: 242 s, s(x) = 3; hyperoxia: 231 s, s(x) = 3; hyperoxia + glutamine: 228 s, s(x) = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased DeltaVO(2max) in normoxia, but not hyperoxia (interaction drink/FiO(2), P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise.
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Affiliation(s)
- Simon Marwood
- Health and Biology, Liverpool Hope University, Liverpool, UK.
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11
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Wilkerson DP, Berger NJA, Jones AM. Influence of hyperoxia on pulmonary O2 uptake kinetics following the onset of exercise in humans. Respir Physiol Neurobiol 2005; 153:92-106. [PMID: 16309978 DOI: 10.1016/j.resp.2005.09.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 09/13/2005] [Accepted: 09/14/2005] [Indexed: 11/21/2022]
Abstract
The purpose of this study was to examine the influence of hyperoxic gas (50% O2 in N2) inspiration on pulmonary oxygen uptake (V(O2)) kinetics during step transitions to moderate, severe and supra-maximal intensity cycle exercise. Seven healthy male subjects completed repeat transitions to moderate (90% of the gas exchange threshold, GET), severe (70% of the difference between the GET and V(O2) peak) and supra-maximal (105% V(O2) peak) intensity work rates while breathing either normoxic (N) or hyperoxic (H) gas before and during exercise. Hyperoxia had no significant effect on the Phase II V(O2) time constant during moderate (N: 28+/-3s versus H: 31+/-7s), severe (N: 32+/-9s versus H: 33+/-6s) or supra-maximal (N: 37+/-9s versus H: 37+/-9s) exercise. Hyperoxia resulted in a 45% reduction in the amplitude of the V(O2) slow component during severe exercise (N: 0.60+/-0.21 L min(-1) versus H: 0.33+/-0.17 L min(-1); P < 0.05) and a 15% extension of time to exhaustion during supra-maximal exercise (N: 173+/-28 s versus H: 198+/-41 s; P < 0.05). These results indicate that the Phase II V(O2) kinetics are not normally constrained by (diffusional) O2 transport limitations during moderate, severe or supra-maximal intensity exercise in young healthy subjects performing upright cycle exercise.
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Affiliation(s)
- Daryl P Wilkerson
- Department of Exercise and Sport Science, Manchester Metropolitan University, Hassall Road, Alsager ST7 2HL, United Kingdom
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Hodges LD, Brodie DA, Bromley PD. Validity and reliability of selected commercially available metabolic analyzer systems. Scand J Med Sci Sports 2005; 15:271-9. [PMID: 16181250 DOI: 10.1111/j.1600-0838.2005.00477.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Automated metabolic gas analysis systems have advanced considerably over the past decade. They provide an abundance of information, which is not possible by using the traditional Douglas bag method and have become an essential tool in both physiological monitoring and in the diagnosis of cardiopulmonary disease. The validity and reliability of the different online metabolic analyzer systems are not well known, with relatively few independent studies being published. The purpose of this review was to examine and evaluate current literature regarding the validity and reliability of commercially available metabolic analyzer systems. This review reveals significant differences between the available systems in the way that they capture and process basic respiratory measurements. Online metabolic analyzer systems were found to vary significantly when compared with Douglas bag methods. These variations have the potential to introduce error into the accuracy with which the health of cardiovascular system can be assessed or training loads can be assigned. Compounding this is the fact that many automated systems are a "black box", which makes it easy to generate data without the user having much understanding of how the data were generated. In conclusion automated metabolic analyser systems are a scientifically robust method for the evaluation of cardiopulmonary function. Individual researchers and clinicians must, however, be able to make their own decisions about the level of error that is tolerable for their individual needs. This presents a significant practical challenge in light of the speed with which technical developments in the field occur and we make some suggestions for the formulation of intersystem comparison studies.
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Affiliation(s)
- L D Hodges
- Research Centre for Health Studies, Buckinghamshire Chilterns University College, Buckinghamshire, UK.
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13
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Grataloup O, Prieur F, Busso T, Castells J, Favier FB, Denis C, Benoit H. Effect of hyperoxia on maximal O2 uptake in exercise-induced arterial hypoxaemic subjects. Eur J Appl Physiol 2005; 94:641-5. [PMID: 15942771 DOI: 10.1007/s00421-005-1361-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2005] [Indexed: 10/25/2022]
Abstract
This study focuses on the effect of hyperoxia on maximal oxygen uptake VO2max and maximal power (Pmax) in subjects exhibiting exercise-induced arterial hypoxemia (EIH) at sea level. Sixteen competing male cyclists VO2max > 60 ml.min(-1).kg(-1)) performed exhaustive ramp exercise (cycle-ergometer) under normoxia and moderate hyperoxia (FIO2 = 30%). After the normoxic trial, the subjects were divided into those demonstrating EIH during exercise [arterial O2 desaturation (delta SaO2) >5%; n = 9] and those who did not (n = 7). Under hyperoxia, SaO2 raised and the increase was greater for the EIH than for the non-EIH group (P<0.001). VO2max improved for both groups and to a greater extent for EIH (12.8 +/- 5.7% vs. 4.2 +/- 4.6%, P<0.01; mean+/-SD) and the increase was correlated to the gain in SaO2 for all subjects (r = 0.71, P<0.01). Pmax improved by 3.3 +/- 3.3% (P<0.01) regardless of the group. These data suggest that pulmonary gas exchange contributes to a limitation in VO2max and power for especially EIH subjects.
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Affiliation(s)
- Olivier Grataloup
- Unité de recherche Physiologie et physiopathologie de l'Exercice et Handicap, Université Jean Monnet, CHU de Saint Etienne, Hôpital Bellevue, Médecine du Sport et Myologie, Saint-Etienne, France.
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Rousseau A, Bak Z, Janerot-Sjöberg B, Sjöberg F. Acute hyperoxaemia-induced effects on regional blood flow, oxygen consumption and central circulation in man. ACTA ACUST UNITED AC 2005; 183:231-40. [PMID: 15743383 DOI: 10.1111/j.1365-201x.2005.01405.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM Despite numerous in vitro and animal studies, circulatory effects and mechanisms responsible for the vasoconstriction seen during hyperoxaemia are yet to be ascertained. The present study set out to: (i) set up a non-invasive human model for the study of hyperoxia-induced cardiovascular effects, (ii) describe the dynamics of this effect and (iii) determine whether hyperoxaemia also, by vasoconstriction alters oxygen consumption (O(2)). METHODS The study comprised four experiments (A, B, C and D) on healthy volunteers examined before, during and after 100% oxygen breathing. A: Blood flow (mL min(-1).100 mL(-1) tissue), venous occlusion plethysmography was assessed (n = 12). B: Blood flow was recorded with increasing transcutaneous oxygen tension (P(tc)O(2)) levels (dose-response) (n = 8). C: Heart rate (HR), stroke volume, cardiac output (CO) and systemic vascular resistance (SVR) was assessed using echocardiography (n = 8). D: O(2) was measured using an open circuit technique when breathing an air-O(2) mix (fraction of inhaled oxygen: F(i)O(2) = 0.58) (n = 8). RESULTS Calf blood flow decreased 30% during O(2) breathing. The decrease in calf blood flow was found to be oxygen dose dependent. A similar magnitude, as for the peripheral circulation, of the effect on central parameters (HR/CO and SVR) and in the time relationship was noted. Hyperoxia did not change O(2). An average of 207 (93) mL O(2) per subject was washed in during the experiments. CONCLUSION This model appears suitable for the investigation of O(2)-related effects on the central and peripheral circulation in man. Our findings, based on a more comprehensive (central/peripheral circulation examination) evaluation than earlier made, suggest significant circulatory effects of hyperoxia. Further studies are warranted to elucidate the underlying mechanisms.
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Affiliation(s)
- A Rousseau
- Department of Anaesthesiology and Intensive Care, University Hospital of Linköping, S-581 85 Linköping, Sweden
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Favier FB, Prieur F, Grataloup O, Busso T, Castells J, Denis C, Geyssant A, Benoit H. A high blood lactate induced by heavy exercise does not affect the increase in submaximal VO2 with hyperoxia. Eur J Appl Physiol 2005; 94:107-12. [PMID: 15682323 DOI: 10.1007/s00421-004-1310-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Accepted: 12/09/2004] [Indexed: 10/25/2022]
Abstract
Few studies evidenced an enhancement in oxygen uptake (VO2) during submaximal exercise in hyperoxia. This O2 "overconsumption" seems to increase above the lactate threshold. The aim of this study was to determine whether the hyperoxia-induced enhancement in VO2 may be related to a higher metabolism of lactate. Nine healthy males (aged 23.1 years, mean VO2 max= 53.8 ml min-1 kg-1) were randomized to two series of exercise in either normoxia or hyperoxia corresponding to an inspired O2 fraction (FIO2) of 30%. Each series consisted of 6 min cycling at 50% VO2 max (Moderate1), 5 min cycling at 95%VO2 max (Near Max) and then 6 min at 50% VO2 max (Moderate2). In both series Near Max was performed in normoxia. VO2 was significantly greater under hyperoxia than in normoxia during Moderate1 (2192 +/- 189 vs. 2025 +/- 172 ml min-1) and during Moderate2 (2352 +/- 173 vs. 2180+ /- 193 ml min-1). However, the effect of the high FIO2 was not significantly different on VO2Moderate2 (+172+/-137 ml min-1 with [La] approximately 6 mmol l-1) compared to VO2Moderate1 (+166 +/- 133 ml min-1 with [La] approximately 2.4 mmol l-1). [La] at the onset of Moderate2 was not different between normoxia and hyperoxia (10.1 +/- 2.2 vs. 10.9 +/- 1.6 mmol l-1). The results show that VO2 is significantly increased during moderate exercise in hyperoxia. But this O2 overconsumption was not modified by a high [La] induced by a prior heavy exercise. It could be concluded that lactate accumulation is not directly responsible for the increase in O2 overconsumption with intensity during exercise in hyperoxia.
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Affiliation(s)
- F B Favier
- Unité de recherche Physiologie et Physiopathologie de l'Exercice et Handicap, Faculté de Médecine Saint Etienne, Université Jean Monnet, France.
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