Relationship between oxygen uptake kinetics and performance in repeated running sprints

The purpose of this study was to test the hypothesis that subjects having a shorter time constant for the fast component of \(\dot{V}{\text{O}}_{2}\) kinetics in a transition from rest to constant exercise would maintain their speed for a longer time during repeated sprint exercise (RSE). Eleven male soccer players completed a graded test, two constant exercises at 60% maximal aerobic speed and RSE, consisting of fifteen 40-m sprints alternated with 25 s of active recovery. All the tests were performed on the field (200 m indoor track). The parameters of the \(\dot{V}{\text{O}}_{2}\) kinetics (time delay, time constant, and amplitude of the primary phase) during the two constant exercises were modeled. All subjects elicited \(\dot{V}{\text{O}}_{2{\rm max}}\) during the RSE. A significant correlation was found between \(\dot{V}{\text{O}}_{2{\rm max}}\) and the relative decrease in speed during the 15 sprints (r=0.71; p < 0.05), but not between \(\dot{V}{\text{O}}_{2{\rm max}}\) and the cumulated time for the 15 sprints (r=0.48; p > 0.05). There were significant correlations between the time constant of the primary phase and the relative decrease in speed during the 15 sprints (r=0.80; p < 0.01) and the cumulated time for the 15 sprints (r=0.80; p < 0.01). These results suggest that individuals with faster \(\dot{V}{\text{O}}_{2}\) kinetics during constant load exercise might also have a faster adjustment of \(\dot{V}{\text{O}}_{2}\) during RSE leading to a shorter cumulated time and a lower relative decrease in speed during the 15 sprints.