Obesity does not impair time-course of cardiac autonomic recovery post-exercise in young men

Objective. - This study aimed to evaluate whether obesity impairs cardiac autonomic modulation after maximal cardiopulmonary exercise testing (CPET). Methods. - Thirty-six men (aged 18 to 30 years) were divided into two groups: normal-weight (n = 20, 21.31 +/- 1.57 kg m(-2)) and obese (n = 16, 34.12 +/- 2.46 kg m(-2)). Heart rate variability (HRV) indices - RMSSD (root mean square of successive RRi differences), SDNN (standard deviation of normal-to-normal RRi), high frequency (HF), low frequency (LF) and LF/HF ratio were evaluated at baseline and during 90 min of recovery after a maximal CPET. Results. - There were no differences (P > 0.05) between groups in short-term nor in long-term recovery for heart rate (HR) and HRV indices. Regardless of the group (main effect of time, P < 0.001, Pr = 1.00), the HR remained higher up to 60 min of recovery, and the lnRMSSD and lnSDNN remained lower up to 45 and 30 min of recovery post-exercise in relation to baseline, respectively. Both lnLF, and LF/HF ratio, remained higher up to 45 min of recovery in relation to baseline, and lnHF, did not return to baseline until 90 min post-exercise (main effect of time, P < 0.001, Pr = 0.94 to 1.00). Conclusion. - In young men, time-course of cardiac autonomic recovery post-exercise was not affected through obesity condition. This information can enable the use of non-pharmacological strategies (i. e., physical exercise or a healthy eating lifestyle) for body fat reduction and the early prevention of cardiac autonomic dysfunction, and consequent decreasing in cardiovascular risks. (c) 2023 Published by Elsevier Masson SAS.