Cardiovagal Modulation in Young and Older Male Adults Following Acute Aerobic Exercise

Abstract

AbstractWe compared response patterns of cardiovagal modulation through heart-rate variability (HRV) and baroreflex sensitivity (BRS) indices at 10 and 60 min after an acute bout of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) in active young and older adults. Twelve young (aged 20–40 years) and older (aged 57–76 years) healthy and active male adults performed an isocaloric acute bout of HIIE, MICE, or a non-exercise condition in a randomized order. HRV and BRS indices were analyzed offline with R-R intervals obtained from a supine position. HIIE decreased natural logarithm (Ln) standard deviation of NN intervals (d=−0.53; 95% CI: −0.77 to −0.30 ms, p<0.001), Ln-root mean square of successive differences (d=−0.85; 95% CI: −1.09 to −0.61 ms, p<0.001), Ln-high-frequency power (d=−1.60; 95% CI: −2.11 to −1.10 ms2; p<0.001), and BRS (d=−6.28; 95% CI: −8.91 to −3.64 ms/mmHg, p<0.001) after exercise in young and older adults, whereas MICE did not. Indices returned to baseline after 60 min. We found no evidence of age-associated response patterns in HRV or BRS to a single bout HIIE or MICE in active participants. HIIE reduced cardiovagal modulation in active young and older adults, returning to baseline values 60 min into recovery.