V˙O2 Response in Supramaximal Cycling Time Trial Exercise of 750 to 4000 m

Purpose: Limited research has been done on the V̇O 2 response to time trial exercise in the supramaximal domain or during free range exercise typical of competition. The present study was designed to measure and to model the V̇O 2 response during supramaximal time trial exercise. Methods: Well-trained cyclists (n = 9) performed a 1-min incremental exercise test to obtain maximal power output (P V̇O2max) and four cycle ergometer time trials of different distances (750, 1500, 2500, and 4000 m). Athletes were instructed to finish in as little time as possible. V̇O 2 was measured breath-by-breath and modeled monoexponentially over the first 54 s (750 m) or 114 s (1500, 2500, and 4000 m) of the time trials. Results: Mean P V̇O2max in the incremental test was 383 ± 28 W. Mean V̇O 2max was 4.5 ± 0.2 Lmin -1. All time trials were characterized by an initial burst in power output during the first 15 s (175 ± 23%, 149 ± 14%, 145 ± 14%, 139 ± 10% P V̇O2max) being largest for 750 m. Simultaneously, the mean response time was significantly smaller in 750 m compared with all other trials (18.8 ± 2.2, 20.9 ± 1.9, 20.8 ± 1.5, and 21.2 ± 2.2 s). Conclusion: Near maximal values of V̇O 2 can be reached within 2 min of strenuous exercise. The larger initial burst in power output in 750 m was accompanied by a faster V̇O 2 response and seems to be of importance to trigger the aerobic system maximally. Copyright © 2008 by the American College of Sports Medicine.