Impact of Altitude on Power Output during Cycling Stage Racing.

Laura A Garvican-Lewis,Kevin G Thompson,Yorck Olaf Schumacher,David T Martin,Bradley Clark,Christopher J Gore,Paolo Menaspà,Brian Stephens,Fuhai Ma,Warren Mcdonald,Christos A Ouzounis

doi:10.1371/journal.pone.0143028

Abstract

PurposeThe purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour.MethodsPower 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 laboratory 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 corresponding 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.ResultsPower output was similar between the laboratory power-profile and the race simulation, however MMPs for 5–600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level.ConclusionA reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.

Highlights

Research has described the performance characteristics of historic competitive cycling events that predominantly take place at low altitudes (< 1000 m)
Power output was similar between the laboratory power-profile and the race simulation, maximal mean power output (MMP) for 5–600 s and 15, 60, 240 and 600 s were lower (p 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively
Speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level

Summary

Introduction

Research has described the performance characteristics of historic competitive cycling events that predominantly take place at low altitudes (< 1000 m). Et al [1] determined that cyclists spend most time (~80%) at low to moderate power outputs (2–4.9 W.kg-1) and least time at highest power outputs (>8 W.kg-1) during flat, hilly and criterium races. Others have described cycling events by reporting the typical heart rate response to cycling competition. The heart rate response may vary depending on the type and terrain of an event, mean heart rates for competitive road cycling races are ~135 beats per minute (bpm), with higher values (>140 bpm) for time trials or hilly events [2,3,4,5]. Like heart rate, are largely affected by the type and terrain of a race. Slowest speeds and cadences are reported during hilly events while fastest speeds and cadences are reported during flat races and time trials [1,2,3]

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