SPRINT INTERVAL TRAINING IN HYPOXIA AND EXERCISE PERFORMANCE – A SHORT REVIEW

Hypoxia is often used during training to augment metabolic load and heighten physiological adaptations with the aim of exercise performance improvements. The recently established altitude training method »sprint interval training in hypoxia« (SIH) requires individuals to perform multiple 30 s Wingate sprints under hypoxia, interspersed with 3–5 min recovery periods. As the execution of repeated supramaximal efforts in hypoxia does not seem to be compromised, it was hypothesized that SIH might further augment exercise performance compared to sprint interval training in normoxia (SIT). To elucidate the usefulness of hypoxia during sprint interval training for exercise performance a systematic review of the available literature was conducted. The PubMed, SportDiscusTM, and Web of Science online databases were searched for original articles – published up to March 2023 – assessing changes in exercise performance following SIH and SIT. Six studies (randomized controlled trials (RCTs)) were identified, evaluating SIH interventions lasting 2–6 weeks. Currently, the available scientific literature does not suggest that SIH additively augments exercise performance in comparison to SIT. The potential changes in anaerobic thresholds after SIH, but not after SIT require further investigation to fully elucidate the subsequent effects on exercise performance. Nevertheless, there is evidence to support beneficial peripheral adaptations known to increase the oxidative and glycolytic capacity, especially in type II, fast-twitch fibers, following SIH, but not SIT. These local adaptations could potentially enable superior improvement in exercise performance after long enough SIH training protocols. Future RCTs on SIH and, particularly, on the performance-related underlying mechanisms seem warranted.