Intermittent Normobaric Hypoxic Exposures at Rest: Effects on Performance in Normoxia and Hypoxia
2012 (English)In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 83, no 10, 942-950 p.Article in journal (Refereed) Published
Introduction: It has been speculated that short (similar to 1-h) exposures to intermittent normobaric hypoxia at rest can enhance subsequent exercise performance. Thus, the present study investigated the effect of daily resting intermittent hypoxic exposures (IHE) on peak aerobic capacity and performance under both normoxic and hypoxic conditions. Methods: Eighteen subjects were equally assigned to either a control (CON) or IHE group and performed a 4-wk moderate intensity cycling exercise training (1 h . d(-1), 5 d . wk(-1)). The IHE group additionally performed IHE (60 min) prior to exercise training. IHE consisted of seven cycles alternating between breathing a hypoxic gas mixture (5 min; FlO2 = 0.12-0.09) and room air (3 min; FlO2, = 0.21). Normoxic and hypoxic peak aerobic capacity ((V) over dotO(2peak)) and endurance performance were evaluated before (PRE), during (MID), upon completion (POST), and 10 d after (AFTER) the training period. Results: Similar improvements were observed in normoxic (V) over dotO(2peak) tests in both groups [IHE: Delta(POST-PRE) = +10%; CON: Delta(POST-PRE) = +14%], with no changes in the hypoxic condition. Both groups increased performance time in the normoxic constant power test only [IHE: Delta(POST-PRE) = +108%; CON: Delta(POST-PRE) = +114%], whereas only the IHE group retained this improvement in the AFTER test. Higher levels of minute ventilation were noted in the IHE compared to the CON group at the POST and AFTER tests. Conclusion: Based on the results of this study, the IHE does not seem to be beneficial for normoxic and hypoxic performance enhancement.
Place, publisher, year, edition, pages
2012. Vol. 83, no 10, 942-950 p.
intermittent hypoxemia, endurance training, hypoxic acclimation, performance
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:kth:diva-104695DOI: 10.3357/ASEM.3332.2012ISI: 000309329000003ScopusID: 2-s2.0-84867409424OAI: oai:DiVA.org:kth-104695DiVA: diva2:567074
QC 201506262012-11-122012-11-092015-06-26Bibliographically approved