Abstract Intermittent hypoxia combined with physical training may enhance performance and health parameters but can impair session quality, limiting adaptations. To address these drawbacks, inter-effort recovery hypoxia has been proposed. This study investigated the effects of a 5-week inter-effort recovery hypoxia protocol followed by a 1-week tapering period in recreational runners. Twenty-four men were allocated to an inter-effort recovery hypoxia group (n = 11) or a normoxia group (n = 13) and assessed for body composition, hematological profile, running economy, maximum velocity, and peak oxygen uptake before training (W0), after training (W6), and after tapering (W8). Training consisted of 3 weekly sessions for 5 weeks: a 5-minute warm-up at 60% of maximum velocity, ten 1-minute effort at 120% (wk 1–3) or 130% (wk 4 and 5) of maximum velocity with 2-minute passive recovery, and 5-minute cool-down at 60% of maximum velocity. The inter-effort recovery hypoxia group inhaled hypoxic air (fraction of inspired oxygen=0.136) during warm-up, recovery bouts, and cool-down. Outcomes were analyzed using generalized linear mixed models. Peak oxygen uptake increased in the inter-effort recovery hypoxia group at W6 (+7%) and W8 (+10%), while the normoxia group improved at W8 (+7%), without group differences; running economy improved in the normoxia group at W8 (+10%). No significant changes occurred in erythropoietin, erythrocytes, hemoglobin, reticulocytes, or body composition. The 5-week inter-effort recovery hypoxia protocol enhanced peak oxygen uptake without hematological changes, indicating a feasible and non-erythropoietic strategy for improving aerobic fitness.
Putti et al. (Fri,) studied this question.