Cardiac autonomic modulation post-maximal incremental exercise is not influenced by body mass index in young adult men

Background The purpose of this study was to analyze whether cardiac autonomic modulation recovery at short-term after maximal incremental exercise test in young adults is influenced by the body mass index (BMI). Methods Forty-eight healthy untrained men (22.26 ± 3.08 years old) were evaluated; 18 were normal weight (NW: 21.89 ± 1.75 kg m −2 ), 11 were overweight (Ov: 27.00 ± 1.38 kg m −2 ) and 19 were obese ( O : 34.38 ± 3.36 kg m −2 ). After the maximal incremental exercise test, a 10 min recovery (5 min actively, followed by 5 min passively) was performed to analyze cardiac autonomic modulation recovery. The root mean square successive differences between adjacent RR intervals (RMSSD) and standard deviation of all normal RR intervals (SDNN) indexes were determined in successive non-overlapped 30 s segments transformed in natural logarithmic—Ln. Results LnRMSSD and LnSDNN indexes were reduced at the end of the incremental exercise test and remained reduced throughout 5 min of active recovery, and throughout 5 min after this time compared to baseline resting ( p 0.05) among the groups. However, throughout 5 min (330–600 s) after active recovery, the LnSDNN values were higher than the end of exercise (NW: 0.56 ± 0.19; Ov: 0.56 ± 0.25; O : 0.57 ± 0.16 ms; p