Normobaric Hypoxia Reduces V˙O2 at Different Intensities in Highly Trained Runners

Introduction We sought to determine the effect of low and moderate normobaric hypoxia on oxygen consumption and anaerobic contribution during interval running at different exercise intensities. Methods Eight runners (age, 25 ± 7 yr, V˙O2max: 72.1 ± 5.6 mL·kg−1·min−1) completed three separate interval sessions at threshold (4 × 5 min, 2-min recovery), V˙O2max (8 × 90 s, 90-s recovery), and race pace (10 × 45 s, 1 min 45 s recovery) in each of; normoxia (elevation: 580 m, FiO2: 0.21), low (1400 m, 0.195) or moderate (2100 m, 0.18) normobaric hypoxia. The absolute running speed for each intensity was kept the same at each altitude to evaluate the effect of FiO2 on physiological responses. Expired gas was collected throughout each session, with total V˙O2 and accumulated oxygen deficit calculated. Data were compared using repeated-measures ANOVA. Results There were significant differences between training sessions for peak and total V˙O2, and anaerobic contribution (P
Source: Medicine and Science in Sports and Exercise - Category: Sports Medicine Tags: APPLIED SCIENCES Source Type: research