(V)over-dot-O2 Slow Component is Independent from Critical Power

The aim of this study was to determine whether the amplitude of the (V) over dotO(2) slow component was dependent from Critical Power (CP; the slope of the linear time - distance relationship) in individuals matched for (V) over dotO(2) peak. 30 moderately-trained endurance athletes completed a maximal graded exercise test, 2 randomly ordered constant power tests at 90 and 100% of peak power output (PPO), and 2 constant duration test of 6min at 30 % of the difference between CP and PPO. Afterwards, participants were ranked according to their relative CP (% PPO; a direct measure of aerobic endurance). The median third was excluded to form a low aerobic endurance group (LEG) and a high aerobic endurance group (HEG). A t-test revealed no difference between LEG and HEG in peak oxygen consumption, but a large difference in their relative CP (p < 0.001, effect size = 3.2). A'(2) was similar between groups (626 +/- 96 and 512 +/- 176 ml, corresponding to 26 +/- 4 and 24 +/- 8 % of end exercise oxygen consumption, respectively; NS) and was not associated with relative CP (r = 0.10; NS). These results suggest that increasing CP probably extends the range of exercise intensities over which the (V) over dotO(2) slow component does not develop, but does not decrease the amplitude of this phenomenon once it occurs.