The effects of hyperoxia on exercise performance in the cold

Abstract

This study tested whether hyperoxia improves exercise performance in moderately-cooled individuals, along with the relationship between cold and hyperoxia on cerebral and muscle oxygenation as potential mechanisms for improvement. Twelve healthy trained male cyclists each completed self-paced 15 km time trials (TT) a week apart in three environmental conditions: Neutral (23°C, FiO2: 0.21), Cold (0°C, FiO2: 0.21), and Cold+Hyper (0°C, FiO2: 0.40). Cold conditions were done after participants were passively cooled by 0.5°C rectal temperature. Performance improved with hyperoxia as TT time for Cold+Hyper was faster than Cold, with no difference found compared to Neutral (Neutral: 1479 ± 75s, Cold: 1509 ± 88s, Cold+Hyper: 1482 ± 85s). Cerebral oxygenation in Neutral and Cold+Hyper was higher than Cold throughout the TT, while Cold+Hyper reached similar levels as Neutral by 2.5 km. Improvement in TT time are likely linked to increased O2 availability allowing for improved aerobic metabolism throughout the body.