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Lei TH, Qin Q, Girard O, Mündel T, Wang R, Guo L, Cao Y. Caffeine intake enhances peak oxygen uptake and performance during high-intensity cycling exercise in moderate hypoxia. Eur J Appl Physiol 2024; 124:537-549. [PMID: 37608124 DOI: 10.1007/s00421-023-05295-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/07/2023] [Indexed: 08/24/2023]
Abstract
PURPOSE We investigated whether caffeine consumption can enhance peak oxygen uptake ([Formula: see text]) by increasing peak ventilation during an incremental cycling test, and subsequently enhance time to exhaustion (TTE) during high-intensity cycling exercise in moderate normobaric hypoxia. METHODS We conducted a double-blind, placebo cross-over design study. Sixteen recreational male endurance athletes (age: 20 ± 2 years, [Formula: see text]: 55.6 ± 3.6 ml/kg/min, peak power output: 318 ± 40 W) underwent an incremental cycling test and a TTE test at 80% [Formula: see text] (derived from the placebo trial) in moderate normobaric hypoxia (fraction of inspired O2: 15.3 ± 0.2% corresponding to a simulated altitude of ~ 2500 m) after consuming either a moderate dose of caffeine (6 mg/kg) or a placebo. RESULTS Caffeine consumption resulted in a higher peak ventilation [159 ± 21 vs. 150 ± 26 L/min; P < 0.05; effect size (ES) = 0.31]. [Formula: see text] (3.58 ± 0.44 vs. 3.47 ± 0.47 L/min; P < 0.01; ES = 0.44) and peak power output (308 ± 44 vs. 302 ± 44 W; P = 0.02, ES = 0.14) were higher following caffeine consumption than during the placebo trial. During the TTE test, caffeine consumption enhanced minute ventilation (P = 0.02; ES = 0.28) and extended the TTE (426 ± 74 vs. 358 ± 75 s; P < 0.01, ES = 0.91) compared to the placebo trial. There was a positive correlation between the percent increase of [Formula: see text] following caffeine consumption and the percent increase in TTE (r = 0.49, P < 0.05). CONCLUSION Moderate caffeine consumption stimulates breathing and aerobic metabolism, resulting in improved performance during incremental and high-intensity endurance exercises in moderate normobaric hypoxia.
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Affiliation(s)
- Tze-Huan Lei
- College of Physical Education, Hubei Normal University, Huangshi, China
| | - Qiyang Qin
- School of Athletic Performance, Shanghai University of Sport, Shanghai, 200438, China
| | - Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
| | - Toby Mündel
- Department of Kinesiology, Brock University, St. Catharines, Canada
| | - Ran Wang
- School of Athletic Performance, Shanghai University of Sport, Shanghai, 200438, China
| | - Li Guo
- School of Exercise and Health, Shanghai University of Sport, Shanghai, China
| | - Yinhang Cao
- School of Athletic Performance, Shanghai University of Sport, Shanghai, 200438, China.
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Cao Y, Fujii N, Fujimoto T, Lai YF, Ogawa T, Hiroyama T, Enomoto Y, Nishiyasu T. CO 2-Enriched Air Inhalation Modulates the Ventilatory and Metabolic Responses of Endurance Runners During Incremental Running in Hypobaric Hypoxia. High Alt Med Biol 2022; 23:125-134. [PMID: 35613387 DOI: 10.1089/ham.2021.0114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cao, Yinhang, Naoto Fujii, Tomomi Fujimoto, Yin-Feng Lai, Takeshi Ogawa, Tsutomu Hiroyama, Yasushi Enomoto, and Takeshi Nishiyasu. CO2-enriched air inhalation modulates the ventilatory and metabolic responses of endurance runners during incremental running in hypobaric hypoxia. High Alt Med Biol. 23:125-134, 2022. Aim: We measured the effects of breathing CO2-enriched air on ventilatory and metabolic responses during incremental running exercise under moderately hypobairc hypoxic (HH) conditions. Materials and Methods: Ten young male endurance runners [61.4 ± 6.0 ml/(min·kg)] performed incremental running tests under three conditions: (1) normobaric normoxia (NN), (2) HH (2,500 m), and (3) HH with 5% CO2 inhalation (HH+CO2). The test under NN was always performed first, and then, the two remaining tests were completed in random and counterbalanced order. Results: End-tidal CO2 partial pressure (55 ± 3 vs. 35 ± 1 mmHg), peak ventilation (163 ± 14 vs. 152 ± 12 l/min), and peak oxygen uptake [52.3 ± 5.5 vs. 50.5 ± 4.9 ml/(min·kg)] were all higher in the HH+CO2 than HH trial (all p < 0.01), respectively. However, the duration of the incremental test did not differ between HH+CO2 and HH trials. Conclusion: These data suggest that chemoreflex activation by breathing CO2-enriched air stimulates breathing and aerobic metabolism during maximal intensity exercise without affecting exercise performance in male endurance runners under a moderately hypobaric hypoxic environment.
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Affiliation(s)
- Yinhang Cao
- School of Physical Education and Sport Training, Shanghai University of Sport, Shanghai, China.,Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Naoto Fujii
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Tomomi Fujimoto
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan.,Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan
| | - Yin-Feng Lai
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Takeshi Ogawa
- Division of Art, Music, and Physical Education, Osaka Kyoiku University, Osaka, Japan
| | - Tsutomu Hiroyama
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Yasushi Enomoto
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Takeshi Nishiyasu
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
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Woorons X, Billaut F, Lamberto C. Running exercise with end-expiratory breath holding up to the breaking point induces large and early fall in muscle oxygenation. Eur J Appl Physiol 2021; 121:3515-3525. [PMID: 34532775 DOI: 10.1007/s00421-021-04813-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 09/10/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE The goal of this study was to assess the effects of repeated running bouts with end-expiratory breath holding (EEBH) up to the breaking point on muscle oxygenation. METHODS Eight male runners participated in three randomised sessions each including two exercises on a motorised treadmill. The first exercise consisted in performing 10-12 running bouts with EEBH of maximum duration either (separate sessions) at 60% (active recovery), 80% (passive recovery) or 100% (passive recovery) of the maximal aerobic velocity (MAV). Each repetition started at the onset of EEBH and ended at its release. In the second exercise of the session, subjects replicated the same procedure but with normal breathing (NB). Arterial oxygen saturation (SpO2), heart rate (HR) and the change in vastus lateralis muscle deoxy-haemoglobin/myoglobin (Δ[HHb/Mb]) and total haemoglobin/myoglobin (Δ[THb/Mb]) were continuously monitored throughout exercises. RESULTS On average, the EEBHs were maintained for 10.1 ± 1.1 s, 13.2 ± 1.8 s and 12.2 ± 1.7 s during exercise at 60%, 80% and 100% of MAV, respectively. In the three exercise intensities, SpO2 (mean nadir values: 76.3 ± 2.5 vs 94.5 ± 2.5%) and HR were lower with EEBH than with NB at the end of the repetitions; whereas, the mean Δ[HHb/Mb] (12.6 ± 5.2 vs 7.7 ± 4.4 µm) and Δ[THb/Mb] (- 0.6 ± 2.3 vs 3.8 ± 2.6 µm) were, respectively, higher and lower with EEBH (p < 0.05). CONCLUSION This study showed that performing repeated bouts of running exercises with EEBH up to the breaking point induced a large and early drop in muscle oxygenation compared with the same exercise with NB. This phenomenon was probably the consequence of the strong arterial oxygen desaturation induced by the maximal EEBHs.
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Affiliation(s)
- Xavier Woorons
- Univ. Lille, Univ. Artois, Univ. Littoral Côte d'Opale, EA 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, 59000, Lille, France. .,ARPEH, Association for Research and Promotion of Hypoventilation Training, 18 rue Saint Gabriel, 59800, Lille, France.
| | - François Billaut
- Département de Kinésiologie, Faculté de Médecine, Université Laval, Québec, QC, G1V 0S6, Canada
| | - Christine Lamberto
- UFR de Santé, Médecine et Biologie Humaine, Université Paris 13, Bobigny, France
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Woorons X, Richalet JP. Modelling the relationships between arterial oxygen saturation, exercise intensity and the level of aerobic performance in acute hypoxia. Eur J Appl Physiol 2021; 121:1993-2003. [PMID: 33782716 DOI: 10.1007/s00421-021-04667-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The aim of this study was to establish a model to estimate the level of arterial oxygen saturation (SpO2) and help determine the appropriate hypoxic dose in humans exercising in acute hypoxia. METHODS SpO2 values were collected in seven untrained (UTS) and seven endurance-trained male subjects (ETS) who performed six cycle incremental and maximal tests at sea level and at simulated altitudes of 1000, 1500, 2500, 3500 and 4500 m. Oxygen uptake was continuously measured and maximal oxygen uptake ([Formula: see text]) was determined in each subject and at each altitude. Intensity was expressed as percentage of [Formula: see text]. RESULTS There were strong non-linear relationships between altitude and SpO2 at low, moderate and high intensity both in ETS and UTS (r = 0.97, p < 0.001). SpO2 was significantly correlated to exercise intensity at sea level and at all simulated altitudes in ETS but only from 2500 m in UTS. There were inverse correlations between SpO2 and sea-level [Formula: see text] at all altitudes, which were stronger from 2500 m and with the increase in exercise intensity. The three-variable model we established predicts (p < 0.001) the SpO2 level of individuals exercising in acute hypoxia based on their sea-level [Formula: see text], the intensity of exercise and the altitude level. CONCLUSION The model demonstrates that the drop of SpO2 during exercise in acute hypoxia is larger with the increase in both sea-level [Formula: see text] and exercise intensity. The model also highlights that the pivotal altitude from which the fall in SpO2 is exacerbated is between 2000 and 2500 m, depending on both sea-level [Formula: see text] and exercise intensity.
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Azadan RJ, Agha NH, Kunz HE, Baker FL, Mylabathula PL, Ledoux TA, O'Connor DP, Pedlar CR, Simpson RJ. The effects of normoxic endurance exercise on erythropoietin (EPO) production and the impact of selective β 1 and non-selective β 1 + β 2 adrenergic receptor blockade. Eur J Appl Physiol 2021; 121:1499-511. [PMID: 33646423 DOI: 10.1007/s00421-020-04558-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 11/09/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE Habitual endurance exercise results in increased erythropoiesis, which is primarily controlled by erythropoietin (EPO), yet studies demonstrating upregulation of EPO via a single bout of endurance exercise have been equivocal. This study compares the acute EPO response to 30 min of high versus 90 min of moderate-intensity endurance exercise and whether that response can be upregulated via selective adrenergic receptor blockade. METHODS Using a counterbalanced, cross-over design, fifteen participants (age 28 ± 8) completed two bouts of running (30-min, high intensity vs 90-min, moderate intensity) matched for overall training stress. A separate cohort of fourteen participants (age 31 ± 6) completed three bouts of 30-min high-intensity cycling after ingesting the preferential β1-adrenergic receptor (AR) antagonist bisoprolol, the non-preferential β1 + β2 antagonist nadolol or placebo. Venous blood was collected before, during, and after exercise, and serum EPO levels were determined by ELISA. RESULTS No detectable EPO response was observed during or after high intensity running, however, in the moderate-intensity trial EPO was significantly elevated at both during-exercise timepoints (+ 6.8% ± 2.3% at 15 min and + 8.7% ± 2.2% at 60 min). No significant change in EPO was observed post-cycling or between the trials involving βAR blockade. CONCLUSION Neither training mode (running or cycling), nor beta-blockade significantly influenced the EPO response to 30 min of high-intensity exercise, however, 90 min of moderate-intensity running elevated EPO during exercise, returning to baseline immediately post-exercise. Identifying the optimal mode, duration and intensity required to evoke an EPO response to exercise may help tailor exercise prescriptions designed to maximize EPO response for both performance and clinical applications.
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Cao Y, Ichikawa Y, Sasaki Y, Ogawa T, Hiroyama T, Enomoto Y, Fujii N, Nishiyasu T. Expiratory flow limitation under moderate hypobaric hypoxia does not influence ventilatory responses during incremental running in endurance runners. Physiol Rep 2019; 7:e13996. [PMID: 30714335 PMCID: PMC6360241 DOI: 10.14814/phy2.13996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 01/12/2019] [Indexed: 11/24/2022] Open
Abstract
We tested whether expiratory flow limitation (EFL) occurs in endurance athletes in a moderately hypobaric hypoxic environment equivalent to 2500 m above sea level and, if so, whether EFL inhibits peak ventilation ( V ˙ Epeak ), thereby exacerbating the hypoxia-induced reduction in peak oxygen uptake ( V ˙ O2peak ). Seventeen young male endurance runners performed incremental exhaustive running on separate days under hypobaric hypoxic (560 mmHg) and normobaric normoxic (760 mmHg) conditions. Oxygen uptake ( V ˙ O2 ), minute ventilation ( V ˙ E), arterial O2 saturation (SpO2 ), and operating lung volume were measured throughout the incremental exercise. Among the runners tested, 35% exhibited EFL (EFL group, n = 6) in the hypobaric hypoxic condition, whereas the rest did not (Non-EFL group, n = 11). There were no differences between the EFL and Non-EFL groups for V ˙ Epeak and V ˙ O2peak under either condition. Percent changes in V ˙ Epeak (4 ± 4 vs. 2 ± 4%) and V ˙ O2peak (-18 ± 6 vs. -16 ± 6%) from normobaric normoxia to hypobaric hypoxia also did not differ between the EFL and Non-EFL groups (all P > 0.05). No differences in maximal running velocity, SpO2 , or operating lung volume were detected between the two groups under either condition. These results suggest that under the moderate hypobaric hypoxia (2500 m above sea level) frequently used for high-attitude training, ~35% of endurance athletes may exhibit EFL, but their ventilatory and metabolic responses during maximal exercise are similar to those who do not exhibit EFL.
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Affiliation(s)
- Yinhang Cao
- Faculty of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
| | - Yuhei Ichikawa
- Faculty of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
| | - Yosuke Sasaki
- Faculty of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
- Faculty of EconomicsNiigata Sangyo UniversityKashiwazakiJapan
| | - Takeshi Ogawa
- Department of Physical EducationOsaka Kyoiku UniversityOsakaJapan
| | - Tsutomu Hiroyama
- Faculty of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
| | - Yasushi Enomoto
- Faculty of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
| | - Naoto Fujii
- Faculty of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
| | - Takeshi Nishiyasu
- Faculty of Health and Sport SciencesUniversity of TsukubaIbarakiJapan
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Burtscher M, Niedermeier M, Burtscher J, Pesta D, Suchy J, Strasser B. Preparation for Endurance Competitions at Altitude: Physiological, Psychological, Dietary and Coaching Aspects. A Narrative Review. Front Physiol 2018; 9:1504. [PMID: 30425646 PMCID: PMC6218926 DOI: 10.3389/fphys.2018.01504] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/05/2018] [Indexed: 01/14/2023] Open
Abstract
It was the Summer Olympic Games 1968 held in Mexico City (2,300 m) that required scientists and coaches to cope with the expected decline of performance in endurance athletes and to establish optimal preparation programs for competing at altitude. From that period until now many different recommendations for altitude acclimatization in advance of an altitude competition were proposed, ranging from several hours to several weeks. Those recommendations are mostly based on the separate consideration of the physiology of acclimatization, psychological issues, performance changes, logistical or individual aspects, but there is no review considering all these aspects in their entirety. Therefore, the present work primarily focusses on the period of altitude sojourn prior to the competition at altitude based on physiological and psychological aspects complemented by nutritional and sports practical considerations.
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Affiliation(s)
- Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.,Austrian Society for Alpine and Mountain Medicine, Innsbruck, Austria
| | - Martin Niedermeier
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Johannes Burtscher
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Dominik Pesta
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Jiri Suchy
- Faculty of Physical Education and Sport, Charles University, Prague, Czechia
| | - Barbara Strasser
- Department of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany.,Medical School, Sigmund Freud University, Vienna, Austria
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Nader E, Guillot N, Lavorel L, Hancco I, Fort R, Stauffer E, Renoux C, Joly P, Germain M, Connes P. Eryptosis and hemorheological responses to maximal exercise in athletes: Comparison between running and cycling. Scand J Med Sci Sports 2018; 28:1532-1540. [PMID: 29356101 DOI: 10.1111/sms.13059] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2018] [Indexed: 12/20/2022]
Abstract
We compared the effects of cycling and running exercise on hemorheological and hematological properties, as well as eryptosis markers. Seven endurance-trained subjects randomly performed a progressive and maximal exercise test on a cycle ergometer and a treadmill. Blood was sampled at rest and at the end of the exercise to analyze hematological and blood rheological parameters including hematocrit (Hct), red blood cell (RBC) deformability, aggregation, and blood viscosity. Hemoglobin saturation (SpO2), blood lactate, and glucose levels were also monitored. Red blood cell oxidative stress, calcium content, and phosphatidylserine exposure were determined by flow cytometry to assess eryptosis level. Cycling exercise increased blood viscosity and RBC aggregation whereas it had no significant effect on RBC deformability. In contrast, blood viscosity remained unchanged and RBC deformability increased with running. The increase in Hct, lactate, and glucose concentrations and the loss of weight at the end of exercise were not different between running and cycling. Eryptosis markers were not affected by exercise. A significant drop in SpO2 was noted during running but not during cycling. Our study showed that a progressive and maximal exercise test conducted on a cycle ergometer increased blood viscosity while the same test conducted on a treadmill did not change this parameter because of different RBC rheological behavior between the 2 tests. We also demonstrated that a short maximal exercise does not alter RBC physiology in trained athletes. We suspect that exercise-induced hypoxemia occurring during running could be at the origin of the RBC rheological behavior differences with cycling.
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Affiliation(s)
- E Nader
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Équipe "Biologie Vasculaire et du Globule Rouge", Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France
| | - N Guillot
- Univ-Lyon, CarMeN Laboratory, INSERM 1060, INRA 1397, Université Claude Bernard Lyon 1, INSA Lyon, Villeurbanne, France
| | - L Lavorel
- Hospices Civils de Lyon, Service d'Exploration Fonctionnelle Respiratoire, Hôpital Croix Rousse, Lyon, France
| | - I Hancco
- Hospices Civils de Lyon, Service d'Exploration Fonctionnelle Respiratoire, Hôpital Croix Rousse, Lyon, France
| | - R Fort
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Équipe "Biologie Vasculaire et du Globule Rouge", Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France.,Hospices Civils de Lyon, Service de Médecine Interne, Hôpital Edouard Herriot, Lyon, France
| | - E Stauffer
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Équipe "Biologie Vasculaire et du Globule Rouge", Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France.,Hospices Civils de Lyon, Centre de Médecine du Sommeil et des Maladies Respiratoires, Hôpital Croix Rousse, Lyon, France
| | - C Renoux
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Équipe "Biologie Vasculaire et du Globule Rouge", Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France.,Hospices Civils de Lyon, Centre de Biologie et de Pathologie Est, Biochimie des Pathologies Erythrocytaires, Bron, France
| | - P Joly
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Équipe "Biologie Vasculaire et du Globule Rouge", Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France.,Hospices Civils de Lyon, Centre de Biologie et de Pathologie Est, Biochimie des Pathologies Erythrocytaires, Bron, France
| | - M Germain
- Hospices Civils de Lyon, Service d'Exploration Fonctionnelle Respiratoire, Hôpital Croix Rousse, Lyon, France
| | - P Connes
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Équipe "Biologie Vasculaire et du Globule Rouge", Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France.,Institut Universitaire de France (IUF), Paris, France
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Affiliation(s)
- D. A. Cardinale
- Åstrand Laboratory, The Swedish School of Sport and Health Sciences, Stockholm, Sweden
- Elite Performance Centre, Bosön - Swedish Sports Confederation, Lidingö, Sweden
| | - B. Ekblom
- Åstrand Laboratory, The Swedish School of Sport and Health Sciences, Stockholm, Sweden
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10
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Chéhère B, Bougault V, Gicquello A, Wallaert B. Cardiorespiratory Response to Different Exercise Tests in Interstitial Lung Disease. Med Sci Sports Exerc 2017; 48:2345-2352. [PMID: 27434081 DOI: 10.1249/mss.0000000000001051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION The 6-min stepper test (6MST) has been used as an alternative to the 6-min walk test (6MWT) to assess exercise tolerance in patients with interstitial lung disease (ILD). Recent data suggest that the tests may involve different energy pathways and cardiorespiratory responses. We thus aimed to compare the cardiorespiratory responses of ILD patients during the 6MWT and the 6MST. METHODS Thirty-one patients with ILD were randomized to perform both tests in the order 6MST → 6MWT (n = 16) or 6MWT → 6MST (n = 15). Gas exchange, HR, and pulse O2 saturation (SpO2) were measured continuously, and dyspnoea, leg discomfort, and blood lactate concentration were assessed before and immediately after each test. RESULTS Oxygen uptake (V˙O2) was lower (P = 0.002) and respiratory equivalent ratio for O2 (V˙E/V˙O2) and RER were higher (both P < 0.001) during the 6MST compared with the 6MWT. The 6MST was also associated with higher blood lactate concentrations (6MST, 4.16 ± 1.95 mmol·L; 6MWT, 2.84 ± 1.17 mmol·L; P = 0.01), higher leg discomfort scores (6MST 5 ± 3 points, 6MWT 3 ± 2 points; P < 0.001), and smaller decreases in SpO2 (6MST -5% ± 5%, 6MWT -9% ± 6%; P < 0.001). CONCLUSIONS ILD patients exhibited greater ventilatory responses and lower arterial O2 desaturation during the 6MST compared with the 6MWT. The higher lactate concentrations and perceived muscle fatigue observed during the 6MST may indicate the presence of intertest differences in active muscle metabolism that could contribute to the distinct cardiorespiratory responses.
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Affiliation(s)
- Baptiste Chéhère
- 1Univ. Lille, EA 7369-URePSSS-Multidisciplinary Research Unit in Sport Health Society, Lille, FRANCE; and 2Service of Pneumology and Immuno-Allergology, Competence Centre for Rare Lung Diseases, Calmette Hospital, Lille, FRANCE
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11
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Constantini K, Tanner DA, Gavin TP, Harms CA, Stager JM, Chapman RF. Prevalence of Exercise-Induced Arterial Hypoxemia in Distance Runners at Sea Level. Med Sci Sports Exerc 2017; 49:948-954. [PMID: 28009787 DOI: 10.1249/mss.0000000000001193] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE It has been reported that ~50% of endurance-trained men demonstrate exercise-induced arterial hypoxemia (EIAH) during heavy exercise. However, this often-cited prevalence rate comes from a single study using a cohort of 25 highly trained men who completed maximal cycle ergometry. As arterial oxyhemoglobin saturation (SpO2) during maximal exercise is reported to be significantly lower during treadmill versus cycle ergometry in the same subjects, we hypothesized that the prevalence of EIAH would be greater than previously reported (and commonly referenced) in a larger cohort of highly endurance-trained men during maximal treadmill running. METHODS Data from 124 highly trained male distance runners (V˙O2max range = 60.3-84.7 mL·kg·min) were retrospectively examined from previously published studies completed in the Indiana University Human Performance Laboratory. Subjects completed a constant speed, progressive-grade treadmill exercise test to volitional exhaustion, and arterial oxyhemoglobin saturation (SaO2ear) in all subjects was estimated using the same oximeter (Hewlett Packard 47201A). RESULTS Using similar inclusion criteria as previously published for highly trained (V˙O2max > 68 mL·kg·min) and for EIAH (SaO2ear ≤ 91%), 55 of 79 subjects (70%) exhibited exercise-induced arterial desaturation. Across all 124 subjects, 104 (84%) demonstrated at least moderate EIAH (SaO2ear ≤ 93%) during maximal treadmill exercise. SaO2ear was significantly yet weakly correlated with V˙E/V˙O2 (P < 0.01, r = 0.28) and V˙E/V˙CO2 (P < 0.001, r = 0.33) but not with V˙O2max. CONCLUSION These results indicate that the prevalence of EIAH in highly trained men during maximal treadmill exercise at sea level is greater compared with previously suggested data, with exercise mode perhaps playing a factor in the number of athletes who experience EIAH.
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Affiliation(s)
- Keren Constantini
- 1HH Morris Human Performance Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN; 2Department of Health and Kinesiology, Purdue University, West Lafayette, IN; and 3Department of Kinesiology, Kansas State University, Manhattan, KS
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Strand TE, Khiabani HZ, Boico A, Radiloff D, Zhao Y, Hamilton KL, Christians U, Klawitter J, Noveck RJ, Piantadosi CA, Bell C, Irwin D, Schroeder T. The novel combination of theophylline and bambuterol as a potential treatment of hypoxemia in humans. Can J Physiol Pharmacol 2017; 95:1009-1018. [PMID: 28467859 DOI: 10.1139/cjpp-2016-0635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hypoxemia can be life-threatening, both acutely and chronically. Because hypoxemia causes vascular dysregulation that further restricts oxygen availability to tissue, it can be pharmacologically addressed. We hypothesized that theophylline can be safely combined with the β2-adrenergic vasodilator bambuterol to improve oxygen availability in hypoxemic patients. Ergogenicity and hemodynamic effects of bambuterol and theophylline were measured in rats under hypobaric and normobaric hypoxia (12% O2). Feasibility in humans was assessed using randomized, double-blind testing of the influence of combined slow-release theophylline (300 mg) and bambuterol (20 mg) on adverse events (AEs), plasma K+, pulse, blood pressure, and drug interaction. Both drugs and their combination significantly improved hypoxic endurance in rats. In humans, common AEs were low K+ (<3.5 mmol/L; bambuterol: 12, theophylline: 4, combination: 13 episodes) and tremors (10, 0, 14 episodes). No exacerbation or serious AE occurred when drugs were combined. A drop in plasma K+ coincided with peak bambuterol plasma concentrations. Bambuterol increased heart rate by approximately 13 bpm. Drug interaction was present but small. We report promise, feasibility, and relative safety of combined theophylline and bambuterol as a treatment of hypoxemia in humans. Cardiac safety and blood K+ will be important safety endpoints when testing these drugs in hypoxemic subjects.
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Affiliation(s)
- Trond-Eirik Strand
- a Norwegian Armed Forces Medical Services, Institute of Aviation Medicine, 0313 Oslo, Norway
| | - Hasse Z Khiabani
- b Department of Pharmacology, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
| | - Alina Boico
- c Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Yulin Zhao
- c Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Karyn L Hamilton
- e Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523, USA
| | - Uwe Christians
- f iC42 Integrated Solutions in Clinical Research and Development, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jelena Klawitter
- f iC42 Integrated Solutions in Clinical Research and Development, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Robert J Noveck
- g Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Christopher Bell
- e Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523, USA
| | - David Irwin
- i Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Thies Schroeder
- i Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA.,j Department of Biochemistry and Pharmacology, University of Mainz, 55128 Mainz, Germany
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Townsend NE, Gore CJ, Ebert TR, Martin DT, Hahn AG, Chow CM. Ventilatory acclimatisation is beneficial for high-intensity exercise at altitude in elite cyclists. Eur J Sport Sci 2016; 16:895-902. [PMID: 26894371 DOI: 10.1080/17461391.2016.1139190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AIM The aim of this study was to examine the relationship between ventilatory adaptation and performance during altitude training at 2700 m. METHODS Seven elite cyclists (age: 21.2 ± 1.1 yr, body mass: 69.9 ± 5.6 kg, height 176.3 ± 4.9 cm) participated in this study. A hypoxic ventilatory response (HVR) test and a submaximal exercise test were performed at sea level prior to the training camp and again after 15 d at altitude (ALT15). Ventilation (VE), end-tidal carbon-dioxide partial pressure (PETCO2) and oxyhaemoglobin saturation via pulse oximetry (SpO2) were measured at rest and during submaximal cycling at 250 W. A hill climb (HC) performance test was conducted at sea level and after 14 d at altitude (ALT14) using a road of similar length (5.5-6 km) and gradient (4.8-5.3%). Power output was measured using SRM cranks. Average HC power at ALT14 was normalised to sea level power (HC%). Multiple regression was used to identify significant predictors of performance at altitude. RESULTS At ALT15, there was a significant increase in resting VE (10.3 ± 1.9 vs. 12.2 ± 2.4 L·min(-1)) and HVR (0.34 ± 0.24 vs. 0.71 ± 0.49 L·min(-1)·%(-1)), while PETCO2 (38.4 ± 2.3 vs. 32.1 ± 3.3 mmHg) and SpO2 (97.9 ± 0.7 vs. 94.0 ± 1.7%) were reduced (P < .05). Multiple regression revealed ΔHVR and exercise VE at altitude as significant predictors of HC% (adjusted r(2) = 0.913; P = 0.003). CONCLUSIONS Ventilatory acclimatisation occurred during a 2 wk altitude training camp in elite cyclists and a higher HVR was associated with better performance at altitude, relative to sea level. These results suggest that ventilatory acclimatisation is beneficial for cycling performance at altitude.
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Affiliation(s)
- Nathan E Townsend
- a Athlete Health and Performance Research Centre , Aspetar Orthopaedic and Sports Medicine Hospital , Doha , Qatar.,b School of Exercise and Nutrition Sciences, Deakin University , Burwood , Australia
| | - Christopher J Gore
- c Department of Physiology , Australian Institute of Sport , Canberra , Australia
| | - Tammie R Ebert
- c Department of Physiology , Australian Institute of Sport , Canberra , Australia
| | - David T Martin
- c Department of Physiology , Australian Institute of Sport , Canberra , Australia
| | - Allan G Hahn
- c Department of Physiology , Australian Institute of Sport , Canberra , Australia
| | - Chin-Moi Chow
- d School of Exercise and Sport Science, University of Sydney , Lidcombe , Australia
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Dittrich N, de Lucas RD, Beneke R, Guglielmo LG. Time to exhaustion at continuous and intermittent maximal lactate steady state during running exercise. Int J Sports Physiol Perform 2014; 9:772-6. [PMID: 24235775 DOI: 10.1123/ijspp.2013-0403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of this study was to determine and compare the time to exhaustion (TE) and the physiological responses at continuous and intermittent (ratio 5:1) maximal lactate steady state (MLSS) in well-trained runners. Ten athletes (32.7 ± 6.9 y, VO2max 61.7 ± 3.9 mL · kg-1 · min-1) performed an incremental treadmill test, three to five 30-min constant-speed tests to determine the MLSS continuous and intermittent (5 min of running, interspaced by 1 min of passive rest), and 2 randomized TE tests at such intensities. Two-way ANOVA with repeated measures was used to compare the changes in physiological variables during the TE tests and between continuous and intermittent exercise. The intermittent MLSS velocity (MLSSint = 15.26 ± 0.97 km/h) was higher than in the continuous model (MLSScon = 14.53 ± 0.93 km/h), while the TE at MLSScon was longer than MLSSint (68 ± 11 min and 58 ± 15 min, P < .05). Regarding the cardiorespiratory responses, VO2 and respiratory-exchange ratio remained stable during both TE tests while heart rate, ventilation, and rating of perceived exertion presented a significant increase in the last portion of the tests. The results showed a higher tolerance to exercising during MLSScon than during MLSSint in trained runners. Thus, the training volume of an extensive interval session (ratio 5:1) designed at MLSS intensity should take into consideration this higher speed at MLSS and also the lower TE than with continuous exercise.
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Tanner DA, Duke JW, Stager JM. Ventilatory patterns differ between maximal running and cycling. Respir Physiol Neurobiol 2013; 191:9-16. [PMID: 24211317 DOI: 10.1016/j.resp.2013.10.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/25/2013] [Accepted: 10/29/2013] [Indexed: 10/26/2022]
Abstract
To determine the effect of exercise mode on ventilatory patterns, 22 trained men performed two maximal graded exercise tests; one running on a treadmill and one cycling on an ergometer. Tidal flow-volume (FV) loops were recorded during each minute of exercise with maximal loops measured pre and post exercise. Running resulted in a greater VO2peak than cycling (62.7±7.6 vs. 58.1±7.2mLkg(-1)min(-1)). Although maximal ventilation (VE) did not differ between modes, ventilatory equivalents for O2 and CO2 were significantly larger during maximal cycling. Arterial oxygen saturation (estimated via ear oximeter) was also greater during maximal cycling, as were end-expiratory (EELV; 3.40±0.54 vs. 3.21±0.55L) and end-inspiratory lung volumes, (EILV; 6.24±0.88 vs. 5.90±0.74L). Based on these results we conclude that ventilatory patterns differ as a function of exercise mode and these observed differences are likely due to the differences in posture adopted during exercise in these modes.
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Affiliation(s)
- David A Tanner
- Human Performance Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN, USA
| | - Joseph W Duke
- Human Performance Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN, USA
| | - Joel M Stager
- Human Performance Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN, USA.
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Abstract
UNLABELLED Whereas the prevalence of exercise-induced hypoxemia (EIH) in endurance athletes is commonly reported as approximately 50%, most previous studies have not corrected PaO2 for exercise-induced hyperthermia. Furthermore, although a detrimental effect on aerobic performance has been assumed, no study has measured arterial oxygen content (CaO2) in this context. PURPOSE To determine the effect of temperature-correcting PaO2 values for rectal, arterial blood, esophageal, and exercising muscle temperatures during exercise on CaO2 and the prevalence of EIH. METHODS Twenty-three trained males (age 26 +/- 5 yr; VO2peak 65.2 +/- 1.6 mL x kg-1 x min-1) performed incremental treadmill exercise to exhaustion with PaO2 corrected for simultaneous temperature measurements at all four sites. EIH was defined as DeltaPaO2 >or= 10 mm Hg. RESULTS : With no temperature correction, DeltaPaO2 was -20.8 +/- 5.0 mm Hg and prevalence was 96% (n = 23), but when corrected for rectal temperature, DeltaPaO2 was -14.7 +/- 7.8 mm Hg and prevalence was 73% (n = 20); for arterial blood temperature, DeltaPaO2 was -7.7 +/- 6.5 mm Hg and prevalence was 35% (n = 20); and for esophageal temperature, DeltaPaO2 was -8.1 +/- 7.7 mm Hg and prevalence was 48% (n = 23), although when corrected for active muscle temperature, DeltaPaO2 was +8.2 +/- 7.8 mm Hg and prevalence was 0% (n = 10). There were no significant changes in CaO2 except for uncorrected values, and there was no correlation between DeltaPaO2 and VO2peak. CONCLUSIONS Although the prevalence of EIH depends on the temperature correction applied to PaO2 values, in no case is there a significant change in CaO2 or any relationship with maximal aerobic power.
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Affiliation(s)
- Garry C Scroop
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia
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Galy O, Hue O, Chamari K, Boussana A, Chaouachi A, Préfaut C. Influence of performance level on exercise-induced arterial hypoxemia during prolonged and successive exercise in triathletes. Int J Sports Physiol Perform 2008; 3:482-500. [PMID: 19223673 DOI: 10.1123/ijspp.3.4.482] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To study the relationship between performance and exercise-induced arterial hypoxemia (EIAH), 5 internationally ranked (INT) and 8 regionally ranked (REG) triathletes performed cycle-run successions (CR) and control runs (R) in competition-like conditions: at approximately 75% VO2max. METHODS Ventilatory parameters and oxyhemoglobin saturation (SpO2) data were collected continuously. Arteriolized partial pressure in O2 (PaO2) and alveolar ventilation (VA) were measured before and after cycling (CRcycle), the successive run (CRrun), and R. Pulmonary diffusing capacity (DLco) was measured at rest and 10 minutes post-CR. Training and short-distance triathlon data were collected. RESULTS INT showed significantly greater experience than REG in competition years (P>.05), training regimen (P>.05), and swimming (P>.05), and cycling (P>.05) volumes; running showed a trend (P<.06). Cycling, running, and total triathlon performances were significantly higher in INT than REG (P>.01). SpO2 during CR dropped significantly more in INT than in REG. Both groups showed significant inverse correlations between the magnitude of the SpO2 change from CRcycle to CRrun and the triathlon running time (r=-0.784; P<.05 and r=-0.699; P<.05; respectively). When compared with CRcycle, PaO2 significantly decreased and VA significantly increased after CRrun and R in both groups (P<.01). DLco significantly dropped between pre- and postexercise in CR and R with no between-group difference (P<.05). CONCLUSIONS EIAH was aggravated in higher performers during simulated cycle-run segments, related to longer experience and heavier training regimens. Possibly, relative hypoventilation caused this aggravated EIAH in INT, although pulmonary diffusion limitation was observed in both groups. Beyond EIAH severity, the magnitude of SpO2 variations during the cycle-run transition may affect triathlon running performance.
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Zavorsky GS, Kim DJ, Christou NV. Compensatory Exercise Hyperventilation is Restored in the Morbidly Obese After Bariatric Surgery. Obes Surg 2008; 18:549-59. [DOI: 10.1007/s11695-008-9437-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 09/11/2007] [Indexed: 10/22/2022]
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Woorons X, Mollard P, Pichon A, Duvallet A, Richalet JP, Lamberto C. Effects of a 4-week training with voluntary hypoventilation carried out at low pulmonary volumes. Respir Physiol Neurobiol 2008; 160:123-30. [PMID: 18160351 DOI: 10.1016/j.resp.2007.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Revised: 09/06/2007] [Accepted: 09/10/2007] [Indexed: 01/26/2023]
Abstract
This study investigated the effects of training with voluntary hypoventilation (VH) at low pulmonary volumes. Two groups of moderately trained runners, one using hypoventilation (HYPO, n=7) and one control group (CONT, n=8), were constituted. The training consisted in performing 12 sessions of 55 min within 4 weeks. In each session, HYPO ran 24 min at 70% of maximal O(2) consumption ( [V(02max)) with a breath holding at functional residual capacity whereas CONT breathed normally. A V(02max) and a time to exhaustion test (TE) were performed before (PRE) and after (POST) the training period. There was no change in V(O2max), lactate threshold or TE in both groups at POST vs. PRE. At maximal exercise, blood lactate concentration was lower in CONT after the training period and remained unchanged in HYPO. At 90% of maximal heart rate, in HYPO only, both pH (7.36+/-0.04 vs. 7.33+/-0.06; p<0.05) and bicarbonate concentration (20.4+/-2.9 mmolL(-1) vs. 19.4+/-3.5; p<0.05) were higher at POST vs. PRE. The results of this study demonstrate that VH training did not improve endurance performance but could modify the glycolytic metabolism. The reduced exercise-induced blood acidosis in HYPO could be due to an improvement in muscle buffer capacity. This phenomenon may have a significant positive impact on anaerobic performance.
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Holmberg HC, Calbet JAL. Insufficient ventilation as a cause of impaired pulmonary gas exchange during submaximal exercise. Respir Physiol Neurobiol 2007; 157:348-59. [PMID: 17303477 DOI: 10.1016/j.resp.2006.12.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 12/18/2006] [Accepted: 12/20/2006] [Indexed: 11/27/2022]
Abstract
Pulmonary ventilation and gas exchange were determined during prolonged skiing (approximately 76% of V(O2, max); cardiac output=26-27 L min(-1)) using diagonal technique (DIA) for 40 min followed by 10 min of double poling (DPOL) and 10 min of leg skiing (LEG). Exercise caused approximately 2-5% reduction of arterial oxygen saturation Sa(O2). For a given cardiac output and V(O2), DPOL presented higher V(E), lower Pa(CO2) and a more efficient pulmonary gas exchange, revealed by higher PA(O2) and Pa(O2) and lower A-aD(O2). The A-aD(O2) widened 2 mmHg L(-1) of cardiac output increase. However, for a given cardiac output and V(O2), exercise mode had an important influence on pulmonary ventilation and gas exchange. Highly trained cross-country skiers' present about 2 units reduction in Sa(O2) from resting values during submaximal exercise at 76% of V(O2, max). Half of the reduction in saturation is accounted for by the rightward-shift of the oxygen dissociation curve of the haemoglobin. The exercise duration has almost no repercussion on pulmonary gas exchange in these athletes, with the small effect on Sa(O2) associated to the increase in body core temperature.
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Affiliation(s)
- H-C Holmberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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Holmberg HC, Rosdahl H, Svedenhag J. Lung function, arterial saturation and oxygen uptake in elite cross country skiers: influence of exercise mode. Scand J Med Sci Sports 2006; 17:437-44. [PMID: 17040487 DOI: 10.1111/j.1600-0838.2006.00592.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Arterial desaturation during exercise is common in endurance-trained athletes, a phenomenon often more pronounced when the muscle mass engaged in the exercise is large. With this background, the present study monitored seven international-level cross country skiers performing on a treadmill while running (RUN), double poling (DP; upper body exercise) and diagonal skiing (DIA; arm and leg exercise). Static and dynamic lung function tests were performed and oxygen uptake was measured during submaximal and maximal exercise. Lung function variables (including the diffusion capacity) were only 5-20% higher than reported in sedentary men. Vital capacity was considerably lower than expected from the skiers' maximal oxygen uptake (VO(2max)), but the maximal ventilation followed a linear relationship with VO(2max). None or only a mild desaturation was observed in DP, RUN and DIA. Blood lactate concentration was slightly higher in DIA than in DP but not different from RUN. In DIA, VO(2max) was 6.23 +/- 0.47 L/min (mean +/- SD), which was 3.8% and 13.9% higher than in RUN and DP, respectively, with similar peak heart rates for the three exercise modes. No relationships were present either between the degree of desaturation and pulmonary functions tests, or with peak oxygen uptakes. The low blood lactate accumulation during the exhaustive efforts contributed to the arterial oxygen saturation being mild in spite of the very high oxygen uptake observed in these skiers.
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Affiliation(s)
- H-C Holmberg
- Department of Physiology & Pharmacology, Karolinska Institute, Stockholm, Sweden.
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Abstract
This study examined the effect of prolonged endurance exercise on the development of exercise-induced hypoxemia (EIH) in athletes who had previously displayed EIH during an incremental maximal exercise test. Five male and three female endurance-trained athletes participated. Susceptibility to EIH was confirmed through a maximal incremental exercise test and defined as a reduction in the saturation of arterial oxygen (SpO(2)) of >/=4% from rest. Sixty minutes of running was conducted, on a separate day, at an oxygen consumption corresponding to 95% of ventilatory threshold. Immediately following the 60 min exercise bout, athletes commenced a time trial to exhaustion at 95% maximal oxygen consumption (VO(2max)). The reduction in SpO(2) was significantly greater during the maximal incremental test, than during the 60 min, or time trial to exhaustion (-8.8+/-1.4%, -3.3+/-1.1%, and -4.1+/-2.3%, P<0.05, respectively). The degree of desaturation during the 60 min was significantly related to the relative intensity of exercise at 95% ventilatory threshold (adjusted r(2)=0.54, P=0.02). In conclusion, athletes who did not exercise at greater than 73% VO(2max) during 60 min of endurance exercise did not display EIH, despite being previously susceptible during an incremental maximal test.
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Affiliation(s)
- I B Stewart
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Qld, Australia.
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Legrand R, Ahmaidi S, Moalla W, Chocquet D, Marles A, Prieur F, Mucci P. O2 arterial desaturation in endurance athletes increases muscle deoxygenation. Med Sci Sports Exerc 2005; 37:782-8. [PMID: 15870632 DOI: 10.1249/01.mss.0000161806.47058.40] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE The aim of this study was to compare the muscle deoxygenation measured by near infrared spectroscopy in endurance athletes who presented or not with exercise-induced hypoxemia (EIH) during a maximal incremental test in normoxic conditions. METHODS Nineteen male endurance sportsmen performed an incremental test on a cycle ergometer to determine maximal oxygen consumption (VO2max) and the corresponding power output (P(max)). Arterial O2 saturation (SaO2) was measured noninvasively with a pulse oxymeter at the earlobe to detect EIH, which was defined as a drop in SaO2 > 4% between rest and the end of the exercise. Muscle deoxygenation of the right vastus lateralis was monitored by near infrared spectroscopy and was expressed in percentage according to the ischemia-hyperemia scale. RESULTS Ten athletes exhibited arterial hypoxemia (EIH group) and the nine others were nonhypoxemic (NEIH group). Training volume, competition level, VO2max, Pmax, and lactate concentration were similar in the two groups. Nevertheless, muscle deoxygenation at the end of the exercise was significantly greater in the EIH group (P < 0.05). CONCLUSION Greater muscle deoxygenation at maximal exercise in hypoxemic athletes seems to be due, at least in part, to reduced oxygen delivery--that is, exercise-induced hypoxemia--to working muscle added to the metabolic demand. In addition, our finding is also consistent with the hypothesis of greater muscle oxygen extraction in order to counteract reduced O2 availability.
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Affiliation(s)
- Renaud Legrand
- Laboratory of Multidisciplinary Analysis of Physical Activity, Faculty of Sport Sciences, University of Artois, Liévin, France
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Laursen PB, Rhodes EC, Langill RH, Taunton JE, McKenzie DC. Exercise-induced arterial hypoxemia is not different during cycling and running in triathletes. Scand J Med Sci Sports 2005; 15:113-7. [PMID: 15773866 DOI: 10.1111/j.1600-0838.2004.00391.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study examined the effect of running and cycling on exercise-induced arterial hypoxemia (EIAH) in individuals well trained in each modality. Thirteen male triathletes (X+/-SD: age=36+/-5 years, mass=69+/-8 kg, body fat=12+/-1%) performed progressive exercise to exhaustion during cycle ergometry and treadmill running. Gas exchange was determined, while oxyhemoglobin saturation (SaO(2)) was measured with an ear oximeter. At maximal exercise, the respiratory exchange ratio (1.15+/-0.06 vs. 1.10+/-0.05) and the ventilatory equivalent for oxygen uptake (37.6+/-3.8 vs. 34.2+/-2.7) were greater during cycling vs. running (P<0.05). However, there were no differences at maximal exercise in oxygen uptake (64.4+/-3.2 vs. 67.0+/-4.6 mL kg(-1) min(-1)), SaO(2) (93.4+/-2.8% vs. 92.6+/-2.2%), or the ventilatory equivalent for carbon dioxide (V(E)/VCO(2); 33.1+/-3.1 vs. 31.0+/-3.1), during cycling vs. running, respectively. During submaximal exercise, the V(E)/VCO(2) was less for cycling (26.0+/-1.0) compared with running (29.1+/-0.4; P<0.05), but this had no apparent effect on the SaO(2) response. In conclusion, EIAH was not significantly different during cycling and running in athletes who were well trained in both exercise modalities.
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Affiliation(s)
- Paul B Laursen
- School of Biomedical and Sports Science, Edith Cowen University, Bldg. 19 Rm. 162, 100 Joondalup Drive, Joondalup, Western Australia 6027, Australia.
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Katayama K, Sato K, Matsuo H, Ishida K, Iwasaki KI, Miyamura M. Effect of intermittent hypoxia on oxygen uptake during submaximal exercise in endurance athletes. Eur J Appl Physiol 2004; 92:75-83. [PMID: 14991325 DOI: 10.1007/s00421-004-1054-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2004] [Indexed: 11/24/2022]
Abstract
The purpose of the present study was to clarify the following: (1) whether steady state oxygen uptake (VO(2)) during exercise decreases after short-term intermittent hypoxia during a resting state in trained athletes and (2) whether the change in VO(2) during submaximal exercise is correlated to the change in endurance performance after intermittent hypoxia. Fifteen trained male endurance runners volunteered to participate in this study. Each subject was assigned to either a hypoxic group (n=8) or a control group (n=7). The hypoxic group spent 3 h per day for 14 consecutive days in normobaric hypoxia [12.3 (0.2)% inspired oxygen]. The maximal and submaximal exercise tests, a 3,000-m time trial, and resting hematology assessments at sea level were conducted before and after intermittent normobaric hypoxia. The athletes in both groups continued their normal training in normoxia throughout the experiment. VO(2) during submaximal exercise in the hypoxic group decreased significantly (P<0.05) following intermittent hypoxia. In the hypoxic group, the 3,000-m running time tended to improve (P=0.06) after intermittent hypoxia, but not in the control group. Neither peak VO(2) nor resting hematological parameters were changed in either group. There were significant (P<0.05) relationships between the change in the 3,000-m running time and the change in VO(2) during submaximal exercise after intermittent hypoxia. The results from the present study suggest that the enhanced running economy resulting from intermittent hypoxia could, in part, contribute to improved endurance performance in trained athletes.
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Affiliation(s)
- Keisho Katayama
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya 464-8601, Japan.
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Abstract
Exercise-induced arterial hypoxaemia is defined as a reduction in the arterial O2 pressure (PaO2) by more than 1 kPa and/or a haemoglobin O2 saturation (SaO2) below 95%. With blood gas analyses ideally reported at the actual body temperature, desaturation is a consistent finding during maximal ergometer rowing. Arterial desaturation is most pronounced at the end of a maximal exercise bout, whereas the reduction in PaO2 is established from the onset of exercise. Exercise-induced arterial hypoxaemia is multifactorial. The ability to maintain a high alveolar O2 pressure (PAO2) is critical for blood oxygenation and this appears to be difficult in large individuals. A large lung capacity and, in turn, diffusion capacity seem to protect PaO2. A widening of the PAO2-PaO2 difference does indicate that a diffusion limitation, a ventilation-perfusion mismatch and/or a shunt influence the transport of O2 from alveoli to the pulmonary capillaries. An inspired O2 fraction of 0.30 reduces the widened PAO2-PaO2 difference by 75% and prevents a reduction of PaO2 and SaO2. With a marked increase in cardiac output, diffusion limitation combined with a fast transit time dominates the O2 transport problem. Furthermore, a postexercise reduction in pulmonary diffusion capacity suggests that the alveolo-capillary membrane is affected. An antioxidant attenuates oxidative burst by neutrophilic granulocytes, but it does not affect PaO2, SaO2 or O2 uptake (VO2), and the ventilatory response to maximal exercise also remains the same. It is proposed, though, that increased concentration of certain cytokines correlates to exercise-induced hypoxaemia as cytokines stimulate mast cells and basophilic granulocytes to degranulate histamine. The basophil count increases during maximal rowing. Equally, histamine release is associated with hypoxaemia and when the release of histamine is prevented, the reduction in PaO2 is attenuated. During maximal exercise, an extreme lactate spill-over to blood allows pH decrease to below 7.1 and according to the O2 dissociation curve this is critical for SaO2. When infusion of sodium bicarbonate maintains a stable blood buffer capacity, acidosis is attenuated and SaO2 increases from 89% to 95%. This enables exercise capacity to increase, an effect also seen when O2 supplementation to inspired air restores arterial oxygenation. In that case, exercise capacity increases less than can be explained by VO2 and CaO2. Furthermore, the change in muscle oxygenation during maximal exercise is not affected when hyperoxia and sodium bicarbonate attenuate desaturation. It is proposed that other organs benefit from enhanced O2 availability, and especially the brain appears to increase its oxygenation during maximal exercise with hyperoxia.
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Affiliation(s)
- Henning Bay Nielsen
- The Copenhagen Muscle Research Centre Department of Anaesthesia, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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Le Creff C, Lecron J, Legros P, Denjean A. Synthèse endogène d’érythropoïétine et hypoxémie induite par l’exercice chez des cyclistes de haut niveau. Sci Sports 2002. [DOI: 10.1016/s0765-1597(02)00153-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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28
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Abstract
To investigate the effects of obesity on the regulation of end-expiratory lung volume (EELV) during exercise we studied nine obese (41 +/- 6% body fat and 35 +/- 7 yr, mean +/- SD) and eight lean (18 +/- 3% body fat and 34 +/- 4 yr) women. We hypothesized that the simple mass loading of obesity would constrain the decrease in EELV in the supine position and during exercise. All subjects underwent respiratory mechanics measurements in the supine and seated positions, and during graded cycle ergometry to exhaustion. Data were analyzed between groups by independent t-test in the supine and seated postures, and during exercise at ventilatory threshold and peak. Total lung capacity (TLC) was reduced in the obese women (P < 0.05). EELV was significantly lower in the obese subjects in the supine (37 +/- 6 vs. 45 +/- 5% TLC) and seated (45 +/- 6 vs. 53 +/- 5% TLC) positions and at ventilatory threshold (41 +/- 4 vs. 49 +/- 5% TLC) (P < 0.01). In conclusion, despite reduced resting lung volumes and alterations in respiratory mechanics during exercise, mild obesity in women does not appear to constrain EELV during cycling nor does it limit exercise capacity. Also, these data suggest that other nonmechanical factors also regulate the level of EELV during exercise.
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Affiliation(s)
- T G Babb
- Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas and The University of Texas Southwestern Medical Center, Dallas, Texas 77231, USA.
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