Training Load Contradicts Cycling Performance When Varying Intensity and Duration

Purpose: To examine the effect of cycling exercise intensity and duration on subsequent performance; and to compare the resulting acute performance decrement (APD) with total work done (TWD) and corresponding training load (TL) metrics. Methods: 14 male cyclists performed a 5-min time-trial (TT) as a baseline, and after 4 initial exercise bouts of varying exercise intensity and duration. The initial exercise bouts were performed in a random order and consisted of a 5- and a 20-min TT, and a 20- and 40-min sub-maximal ride. The resulting APD was calculated as the percentage change in 5-min TT from baseline, and this was compared with the TWD and TL metrics for the corresponding initial exercise bout. Results: Average power output was different for each of the 4 initial exercise bouts (ηp2=0.971; P<0.001), and all bouts resulted in an APD. But APD was only different when comparing maximal to sub-maximal bouts (ηp2=0.862; P<0.001). The APD contradicted TWD and TL metrics, and was not different when comparing 5- and 20-min maximal TT’s, or the 20- and 40-min sub-maximal bouts. In contrast, TL metrics were different for all training sessions (ηp2=0.970; P<0.001). Conclusion: An APD is found after initial exercise bouts consisting of 5- and 20-min TT’s and after 20-, and 40-min of sub-maximal exercise that is not consistent with the corresponding values for TWD or TL. This discrepancy highlights important shortcomings when using TWD and TL to compare exercise bouts of different intensity and duration.