Physiological determinants and energy system contribution in short- and middle-distance cycling performance

The purpose of this study was to investigate the contribution of aerobic and anaerobic energy release on cycling performance in 10 to 180 s.

18 male cyclists from recreational- to elite level participated in this cross-sectional study. The cyclists were tested in oxygen cost of cycling (C), peak oxygen uptake (VO_2peak), maximal sprint power (MSP), and five short time trials (TT): 10 s (10TT), 30 s (30TT), 60 s (60TT), 120 s (120TT) and 180 s (180TT). In all time trials, VO₂, maximal accumulated oxygen deficit (MAOD) and blood lactate concentration ([La^-]_b) were measured.

On average, there was a 50-50% distribution of anaerobic and aerobic energy release at 73 s and at 180TT the distribution was 71% aerobic and 29% anaerobic. When performance was expressed in absolute watt values, strong correlations were found between 180TT and MSP (r = 0.85, p < 0.01, 95% CI [0.55, 0.93]), maximal aerobic power (MAP) (r = 0.88, p < 0.01, 95% CI [0.69, 0.95]), MAOD expressed as mL· kg^- 1 (r = 0.81, p < 0.01, 95% CI [0.56, 0.93]) and 0.7MAP + 0.3MSP (r = 0.91, p < 0.01, 95% CI [0.77, 0.97]). MAOD measured in 180TT correlated significantly with MAOD in all the other TTs, i.e., those with the highest MAOD already at 10 s, also had the highest MAOD at 180s. Furthermore, MAOD increased rapidly between 10 and 60 s, but leveled off between 120 and 180 s. This suggests an individual maximal volume of anaerobic work that needs to be distributed across a given cycling duration.