The study by Robach et al. ¹ aimed to test the hypothesis that LHTL in hypobaric hypoxia improves exercise performance in elite endurance athletes. The authors have to be commended for this logistical challenge of having two VO _2max -matched groups training together between 600 and 1500m but either sleeping at 2207m (LHTL, n = 11) or at 1035 m (Control, n = 8). This protocol allows a good matching of the training loads and it was expected that it could "isolate" the specific effects of hypoxia in the LHTL group. This article is protected by copyright. All rights reserved.