Abstract
PURPOSE: To determine if post-exercise heart rate variability, in the form of logged transformed root mean square of successive differences of the R-R intervals (LnRMSSD) can be measured reliably during the recovery from a submaximal cycle test and what the relationship of LnRMSSD is with training status of the cyclists. METHODS: Fourteen male cyclists participated in the reliability part for the study, which included performing six Lamberts Submaximal Cycle Test (LSCT), during which recovery LnRMSSD was measured over 30 s (LnRMSSD(30 s)), 60 s LnRMSSD(60 s))and 90 s LnRMSSD(90 s)). In addition, fifty male and twenty female cyclists completed a peak power output (PPO) test (including VO(2peak)) and 40 km time trial (40 km TT) before which they performed the LSCT as a standardized warm-up. Relationships between the LnRMSSD and PPO, VO(2peak) and 40 km TT time were studied. RESULTS: Due to the design of the LSCT, submaximal heart and breathing rate were similar at the end of stage 3 of the LSCT, as well as during the recovery periods. The highest reliability was found in LnRMSSD(60 s) (ICC: 0.97) with a typical error of the measurement (TEM: 5.8%). In line with this the strongest correlations were found between LnRMSSD(60 s) and PPO (r = 0.93[male]; 0.85[female]), VO(2peak) (r = 0.71[male]; 0.63[female];) and 40 km TT (r = - 0.83[male]; - 0.63[female]). CONCLUSIONS: LnRMSSD(60 s) can be measured reliably after the LSCT and can predict PPO, VO(2peak) and 40 km TT performance well in trained-to-elite cyclists. These findings suggest that recovery LnRMSSD can potentially play an important role in monitoring and fine-tuning training prescriptions in trained-to-elite cyclists.