Repeated sprint training in normobaric hypoxia

Area of Science:

• Sports Science
• Exercise Physiology
• Environmental Physiology

Background:

• Repeated sprint ability (RSA) is crucial for performance in intermittent sports.
• Repeated sprint training (RST) improves RSA, but the effect of hypoxia is not fully understood.

Purpose of the Study:

• To investigate if training in hypoxia augments adaptations to repeated sprint training compared to normoxia.
• To compare the effects of 4 weeks of hypoxic RST versus normoxic RST on RSA and physiological responses.

Main Methods:

• Thirty male rugby players underwent 12 sessions of RST (10 x 6s sprints, 30s recovery) over 4 weeks.
• Participants trained in either hypoxia (13% FiO₂) or normoxia (21% FiO₂).
• Performance tests (Yo-Yo IFT, RSA test) and physiological measures (heart rate, blood lactate, muscle/cerebral deoxygenation) were assessed pre- and post-training.

Main Results:

• Both groups improved Yo-Yo IFT performance, with significantly greater gains in the hypoxic group (33%) versus the normoxic group (14%).
• Hypoxic training tended to increase oxygen consumption and reduce cerebral deoxygenation during sprints.
• Hypoxic RST led to twofold greater improvements in high-intensity exercise capacity compared to normoxic RST.

Conclusions:

• Four weeks of training in hypoxia can significantly enhance RSA and high-intensity exercise capacity more than equivalent training in normoxia.
• Hypoxic training offers a potent strategy for improving athletic performance in intermittent sports during short training blocks like preseason.
• The findings suggest that hypoxia potentiates the adaptive response to repeated sprint training.