Sex differences in cardiac vagal reactivation from the end of isometric handgrip exercise and at the onset of muscle metaboreflex isolation.

Sex differences in cardiac vagal reactivation from the end of isometric handgrip exercise and at the onset of muscle metaboreflex isolation. Auton Neurosci. 2020 Aug 13;228:102714 Authors: Samora M, Teixeira AL, Sabino-Carvalho JL, Vianna LC Abstract A parasympathetic reactivation is an underlying mechanism mediating the rapid fall in heart rate (HR) at the onset of post-exercise ischemia (PEI) in humans. Herein, we tested the hypothesis that, compared to men, women present a slower HR recovery at the cessation of isometric handgrip exercise (i.e., onset of PEI) due to an attenuated cardiac vagal reactivation. Forty-seven (23 women) young and healthy volunteers were recruited. Subjects performed 90s of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 3-min of PEI. The onset of PEI was analyzed over the first 30s in 10s windows. Cardiac vagal reactivation was indexed using the HR fall and by HR variability metrics (e.g., RMSSD and SDNN) immediately after the cessation of the exercise. HR was significantly increased from rest during exercise in men and women and increases were similar between sexes. However, following the cessation of exercise, the HR recovery was significantly slower in women compared to men regardless of the time point (women vs. men: ∆-14 ± 8 vs. ∆-18 ± 6 beats.min-1 at 10s; ∆-20 ± 9 vs. ∆-25 ± 8 beats.min-1 at 20s; ∆-22 ± 10 vs. ∆-27 ± 9 beats.min-1 at 30...
Source: Autonomic Neuroscience - Category: Neuroscience Authors: Tags: Auton Neurosci Source Type: research