Energetics of indoor track cycling in trained competitors.

Steady-state track VO2 was estimated by means of the retroextrapolation method in seventeen competitive male cyclists at speeds ranging from 28 to 43 km.h-1. Peak VO2 was also determined using an ergocycle multistage test (80 rev.min-1). Results showed large VO2 variations at similar speeds on the track (SEE greater than 10% Y; n = 17). Third degree regressions were the most accurate to describe the evolution of VO2 with speed, while the units ml.kg-0.667.min-1 showed better correlations and lower dispersions than 1.min-1, ml.kg-1.min-1, and 1.min-1.m-2. When categorized according to the Québec Cycling Federation ranking, (elites: n = 6; nonelites: n = 11), the elites tended to demonstrate to a lower mean VO2 for the range of velocities studied. The difference was, however, not statistically significant (P greater than 0.05). Interindividual variations were reduced by expressing VO2 and speed as relative percentages of maximal values in ten subjects: % MAP = 6.475 e exp [0.0274% MAS] where % MAP = track VO2/laboratory peak VO2, and % MAS = speed/speed associated with peak VO2 on the track. No significant difference was observed between track and ergocycle peak VO2 (P greater than 0.05), indicating the validity of the 80 rev.min-1 protocol for laboratory evaluation of racing cyclists. The concept of cycling economy as a contributing factor to performance and applications of the % MAP-% MAS relationship are discussed.