INTERMITTENT HYPOXIA DOES NOT AFFECT MOVEMENT SPEED BUT DOES AFFECT POWER
Wood, M. R., Hamlin, M. J., Hinckson, E. A., & Hopkins, W. G. (2006). Physical performance after adaptation to different protocols of intermittent hypoxia. Medicine and Science in Sports and Exercise, 38(5), Supplement abstract 2732.
Club and junior representative rugby players (N = 15) were assigned to one of four hypoxia groups. All Ss used a personal rebreathing device for 1-hour daily sessions of hypoxia consisting of six intervals of hypoxia interspersed with recovery periods of ambient air. The groups differed in the duration of hypoxia + recovery intervals: 5+5, 6+4, 7+3, and 8+2 min. An initial 15-day loading period of exposures was followed by two five-day maintenance periods, over a total of 45 days. Pulse oximetry was used to progressively reduce each player's oxygen saturation (Day 1, 89-91%, Day 15 onwards, 76-78%). Before and two days after the exposure period, players performed a game-length simulation consisting of 14 circuits, each involving five different sprints and two scrum-like drives.
The effect of the mean dose was mainly trivial for sprint speeds but harmful for drive. Increasing the dose produced a mixture of trivial, beneficial, and harmful differences in sprint speed and an increase in the harmful effect on drive power.
Implication. There was little consistent effect of intermittent hypoxia on sprint speed, and an apparently harmful effect on drive power made worse by increasing the duration of the hypoxic intervals.
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