7-day Simulated Intermittent Hypoxic Training Improves Maximal Aerobic Capacity In 400m Or 800m Runners

Abstract

The effectiveness of short-term (1 week) intermittent hypoxic training for competitive athletes is unclear even though intermittent hypoxic training is currently used by some athletes to enhance performance. We demonstrated that 6 days of intermittent hypoxic exposure and interval training improved performance of maximal anaerobic running test (MART) (ACSM 2014). However, the effectiveness of intermittent hypoxic exposure independent of training is unclear. PURPOSE: The purpose of the present study was to investigate the physiological adaptations in well-trained 400m or 800m runners following 7 days of intermittent hypoxic exposure combined with high intensity interval training. METHODS: Eight well-trained female 400m or 800m runners were assigned to either a hypoxic group (n=8) or a control group (n=8) using a cross-over design. Hypoxic group trained in normobaric hypoxia room (3000m altitude) and control group trained at sea-level (60m altitude). All Subjects trained for 7 days and performed MART and incremental maximal running test before and after the 7-day training period. The training consisted of high intensity interval training (five 30s all-out pedaling) and endurance training (30min incremental running and 30min steady pedaling). Maximal power in the MART was calculated from the running velocity in the last completed bout and running time in the exhaustion bout. VO2max was measured in the incremental running test. All subjects trained and performed tests again in the opposite condition after 5 months. RESULTS: Maximal power in the MART increased significantly (p<0.01) after training period in both groups (Hypoxic: 109.5±1.4 vs. 111.7±2.8, Control: 109.1±2.7 vs. 111.0±2.7 ml/kg/min). VO2max in the hypoxic group increased significantly (p<0.05) after training period (49.7±5.0 vs. 51.6±3.5 ml/kg/min). On the other hand, there were no significant changes in the control group (49.1±4.8 vs. 50.0±5.7 ml/kg/min). CONCLUSIONS: These results suggest that 7 days of intermittent hypoxic exposure combined with high intensity interval training is effective for enhanceming maximal aerobic capacity as well as anaerobic power in 400m or 800m runners.