Heart rate recovery as a guide to monitor fatigue and predict changes in performance parameters.

Determining the optimal balance between training load and recovery contributes to peak performance in well-trained athletes. The measurement of heart rate recovery (HRR) to monitor this balance has become popular. However, it is not known whether the impairment in performance, which is associated with training-induced fatigue, is accompanied by a change in HRR. Therefore, the aim of this study was to retrospectively analyze the relationship between changes in HRR and cycling performance in a group of well-trained cyclists (n=14) who participated in a 4-week high-intensity training (HIT) program. Subjects were assigned to either a group that continuous had a increase in HRR (G(Incr)) or a group that showed a decrease in HRR (G(Decr)) during the HIT period. Both groups, G(Incr) and G(Decr), showed improvements in the relative peak power output (P=0.001 and 0.016, respectively) and endurance performance parameters (P=0.001 and <0.048, respectively). The average power during the 40-km time trial (40-km TT), however, improved more in G(Incr) (P=0.010), resulting in a tendency for a faster 40-km TT time (P=0.059). These findings suggest that HRR has the potential to monitor changes in endurance performance and contribute to a more accurate prescription of training load in well-trained and elite cyclists.