Recovery of heart rate and heart rate variability after a maximal cardiopulmonary exercise test in novice female runners

Purpose Previous studies have shown delayed cardiac vagal reactivation after high-intensity endurance exercise when estimated with heart rate variability (HRV). However, the recovery dynamics of RR intervals (RRI) and HRV after a maximal incremental exercise test have been studied less in non-athletic population and especially in females. The main aim of the study was to examine the recovery dynamics of RRI and HRV immediately after a maximal cardiopulmonary exercise test (CPET) in adult females. Methods Twenty-eight healthy, novice recreational female runners (33.7 +/- 4.2 years) were selected to participate in this study from a larger group of participants (Run RCT). RRIs were collected continuously during a controlled rest, a CPET on a treadmill and a 15-min controlled, passive recovery. Minute-by-minute recovery dynamics were analyzed. Results The dynamic phase of RRI and heart rate recovery (HRR) (from 192.2 +/- 9.9 to 111.4 +/- 2.4, P < 0.001) occurred during the first 4.5 min with HRR of 36 +/- 10 beats during the first minute of the recovery. Resting heart rate was negatively associated (r = - 0.53, P = 0.016) with HRR during the recovery. No recovery of root mean square of successive RRIs (RMSSD) was detected during the 15-min recovery. RMSSD was 15.0 +/- 9.2% of resting values at the end of the recovery. Conclusion No recovery of vagal-derived HRV was detected immediately after a CPET in novice recreational female runners despite marked changes in sympathovagal balance, detected by rapid recovery of RRI during the first 5 min after exercise cessation.