Published in:
01-06-2004 | Original Article
Effect of intermittent hypoxia on oxygen uptake during submaximal exercise in endurance athletes
Authors:
Keisho Katayama, Kohei Sato, Hiroshi Matsuo, Koji Ishida, Ken-ichi Iwasaki, Miharu Miyamura
Published in:
European Journal of Applied Physiology
|
Issue 1-2/2004
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Abstract
The purpose of the present study was to clarify the following: (1) whether steady state oxygen uptake (V̇O2) during exercise decreases after short-term intermittent hypoxia during a resting state in trained athletes and (2) whether the change in V̇O2 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. V̇O2 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 V̇O2 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 V̇O2 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.