Association between resting heart rate with cardiac autonomic modulation during and after a resistance exercise

This study correlated the heart rate (HR) dynamics and parasympathetic activity at rest, during and after a resistance exercise (RE) session with resting heart rate (RHR) in young men.

The RR-interval series was recorded at rest in the supine (sup) and following the postural change (from supine to orthostatic position) in the orthostatic (ort), as well as during and after 15 min of a RE session in 14 young men. We used RHR value in the supine position and the square root of the mean of the square of successive adjacent R-R intervals difference (rMSSD) as the parasympathetic indexes. The statistical analysis employed Pearson and Spearman correlation tests with a two-tailed p value ≤ 0.05.

We observed that HR_ort, relative variation (∆%) of RHR, and HR and relative (%) heart rate recovery (HRR) at five, ten, and fifteen minutes were correlated with RHR (r = from − 0.80 to 0.89, p ≤ 0.02). At rest, rMSSD_sup, rMSSD_ort, and absolute variation (∆) rMSSD were correlated with RHR (r_s = from − 0.53 to − 0.82, p ≤ 0.049); during RE session, we observed a correlation between ∆rMSSD and ∆%rMSSD with RHR (r_s =  − 0.82 to − 0.68, p ≤ 0.01) and after a RE session, rMSSD_5–15 min were correlated with RHR (r_s = from − 0.75 to − 0.86, p ≤ 0.01).

We concluded that young men with lower RHR showed higher HR dynamics and parasympathetic reactivity at rest, higher parasympathetic withdrawal during the RE session, and higher HRR and parasympathetic reactivation after a RE session.