Dietary Nitrate Supplementation Does Not Alter Exercise Efficiency at High Altitude - Further Results From the Xtreme Alps Study.
| Autor: | Hennis PJ; Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom.; SHAPE Research Group, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom., Cumpstey AF; Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom., O'Doherty AF; Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle upon Tyne, United Kingdom., Fernandez BO; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.; Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, United Kingdom., Gilbert-Kawai ET; Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom., Mitchell K; Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom., Moyses H; Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom., Cobb A; Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom., Meale P; Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom., Pöhnl H; AURAPA Würzungen GmbH, Bietigheim-Bissingen, Germany., Mythen MG; Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom., Grocott MPW; Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom., Levett DZH; Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom., Martin DS; Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom.; Peninsula Medical School, University of Plymouth, Plymouth, United Kingdom., Feelisch M; Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.; Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, United Kingdom. |
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| Jazyk: | angličtina |
| Zdroj: | Frontiers in physiology [Front Physiol] 2022 Feb 28; Vol. 13, pp. 827235. Date of Electronic Publication: 2022 Feb 28 (Print Publication: 2022). |
| DOI: | 10.3389/fphys.2022.827235 |
| Abstrakt: | Introduction: Nitrate supplementation in the form of beetroot juice (BRJ) ingestion has been shown to improve exercise tolerance during acute hypoxia, but its effect on exercise physiology remains unstudied during sustained terrestrial high altitude exposure. We hypothesized that performing exercise at high altitude would lower circulating nitrate and nitrite levels and that BRJ ingestion would reverse this phenomenon while concomitantly improving key determinants of aerobic exercise performance. Methods: Twenty seven healthy volunteers (21 male) underwent a series of exercise tests at sea level (SL, London, 75 m) and again after 5-8 days at high altitude (HA, Capanna Regina Margherita or "Margherita Hut," 4,559 m). Using a double-blind protocol, participants were randomized to consume a beetroot/fruit juice beverage (three doses per day) with high levels of nitrate (∼0.18 mmol/kg/day) or a nitrate-depleted placebo (∼11.5 μmoles/kg/day) control drink, from 3 days prior to the exercise trials until completion. Submaximal constant work rate cycle tests were performed to determine exercise efficiency and a maximal incremental ramp exercise test was undertaken to measure aerobic capacity, using breath-by-breath pulmonary gas exchange measurements throughout. Concentrations of nitrate, nitrite and nitrosation products were quantified in plasma samples collected at 5 timepoints during the constant work rate tests. Linear mixed modeling was used to analyze data. Results: At both SL and HA, plasma nitrate concentrations were elevated in the nitrate supplementation group compared to placebo ( P < 0.001) but did not change throughout increasing exercise work rate. Delta exercise efficiency was not altered by altitude exposure ( P = 0.072) or nitrate supplementation ( P = 0.836). V̇O Conclusion: Whilst regularly consumed during an 8 days expedition to terrestrial high altitude, nitrate supplementation did not alter exercise efficiency and other exercise physiological variables, except decreasing V̇O Competing Interests: MG serves on the medical advisory board of Sphere Medical Ltd. and is a director of Oxygen Control Systems Ltd., received honoraria for speaking for and/or travel expenses from BOC Medical (Linde Group), Edwards Lifesciences, and Cortex GmBH, leads the Xtreme-Everest Oxygen Research Consortium and the Fit-4-Surgery research collaboration, and serves as the UK NIHR CRN national specialty group lead for Anaesthesia, Perioperative Medicine and Pain and is an elected council member of the Royal College of Anaesthetists. DM has received lecture and consultancy fees from Siemens Healthineers and Edwards Lifesciences. MM is a paid Consultant for Edwards Lifesciences, his University Chair was sponsored by Smiths Medical, founding Editor of the Journal of Perioperative Medicine and sits on the Editorial Board of the British Journal of Anaesthesia, and Editor-in-Chief of TopMedTalk. HP was employed by the company AURAPA Würzungen GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. (Copyright © 2022 Hennis, Cumpstey, O’Doherty, Fernandez, Gilbert-Kawai, Mitchell, Moyses, Cobb, Meale, Pöhnl, Mythen, Grocott, Levett, Martin, Feelisch and The Xtreme Alps Research Group.) |
| Databáze: | MEDLINE |
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