Purpose: To evaluate the effect of maturity status on the autonomic nervous system at rest and recovery after short-term, high-intensity exercise in adolescents.
Methods: A biological maturity age was estimated in 27 males by calculating the years from peak height velocity (PHV) using a multiple regression equation. Subjects were divided into two groups: pre-PHV (years from PHV < 0.49), N = 14, mean age = 12.29 ± 0.91 yr; post-PHV (years from PHV > 0.5, N = 13, mean age = 15.12 ± 0.76 yr). HR variability was used to evaluate autonomic function. ECG tracings were collected during 5 min at rest and recovery after a Wingate test and were analyzed in the frequency domain (low-frequency (LF), high-frequency (HF), LF/HF, total power (TP)). Data are presented as natural logarithms (LN).
Results: Changes in HR from HRpeak during exercise to HR measured at minute 4 after exercise (ΔHR4) were significantly greater in the pre-PHV group (84.31 ± 17.58 bpm) compared with the post-PHV group (69.42 ± 17.63 bpm). There were no significant differences in resting HR variability between pre- and post-PHV groups (P > 0.05). Significant group × time interactions were found for LFLN (ms2) and TPLN (ms2) measured during recovery (P < 0.05). Post hoc tests showed that the pre-PHV group had significantly higher postexercise LFLN (5.02 ± 0.97 vs 4.19 ± 0.79) and TPLN (6.36 ± 1.02 vs 5.62 ± 0.65) compared with the post-PHV group. When postexercise LFLN (ms2) was normalized for TPLN (ms2), there were no significant differences between groups (P > 0.05).
Conclusion: The pre-PHV group had higher total HR variability than the post-PHV group after a Wingate test, suggesting that maturity status significantly affects total HR variability during recovery after high-intensity exercise.