RESEARCH ARTICLE Impact of Altitude on Power Output during Cycling Stage Racing

Purpose The purpose of this study was to quantify the effects of moderate-high altitude on power out-put, cadence, speed and heart rate during a multi-day cycling tour. Methods Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a labo-ratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corre-sponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000m (<1000m, 1000–2000, 2000–3000 and>3000m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin