Two Days of Hypoxic Exposure Increased Ventilation Without Affecting Performance
- Autores: Sébastien Racinais, Grégoire Millet, Chikei Li, Bronwen Masters, Justin Grantham
- Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 24, Nº. 4, 2010, págs. 985-991
- Idioma: inglés
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Resumen
The aim of this study was to test the short-term effects of using hypoxic rooms before a simulated running event. Thirteen subjects (29 ± 4 years) lived in a hypoxic dormitory (1,800 m) for either 2 nights (n = 6) or 2 days + nights (n = 7) before performing a 1,500-m treadmill test. Performance, expired gases, and muscle electrical activity were recorded and compared with a control session performed 1 week before or after the altitude session (random order). Arterial blood samples were collected before and after altitude exposure. Arterial pH and hemoglobin concentration increased (p < 0.05) and PCO2 decreased (p < 0.05) upon exiting the room. However, these parameters returned (p < 0.05) to basal levels within a few hours. During exercise, mean ventilation (VE) was higher (p < 0.05) after 2 nights or days + nights of moderate altitude exposure (113.0 ± 27.2 L·min-1) than in the control run (108.6 ± 27.8 L·min-1), without any modification in performance (360 ± 45 vs. 360 ± 42 seconds, respectively) or muscle electrical activity. This elevated VE during the run after the hypoxic exposure was probably because of the subsistence effects of the hypoxic ventilatory response. However, from a practical point of view, although the use of a normobaric simulating altitude chamber exposure induced some hematological adaptations, these disappeared within a few hours and failed to provide any benefit during the subsequent 1,500-m run.
