Metaboreflex activation delays heart rate recovery after aerobic exercise in never‐treated hypertensive men

Abstract

Muscle metaboreflex influences heart rate (HR) regulation after aerobic exercise. Therefore, increased metaboreflex sensitivity may help to explain the delayed HR recovery (HRR) reported in hypertension. The present study assessed and compared the effect of metaboreflex activation after exercise on HRR, cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV) in normotensive (NT) and hypertensive (HT) men. Twenty-three never-treated HT and 25 NT men randomly underwent two-cycle ergometer exercise sessions (30 min, 70% V̇O2 peak ) followed by 5 min of inactive recovery performed with (occlusion) or without (control) leg circulatory occlusion (bilateral thigh cuffs inflated to a suprasystolic pressure). HRR was assessed via HR reduction after 30, 60 and 300 s of recovery (HRR30s, HRR60s and HRR300s), as well as by the analysis of short- and long-term time constants of HRR. cBRS was assessed by sequence technique and HRV by the root mean square residual and the root mean square of successive differences between adjacent RR intervals on subsequent 30 s segments. Data were analysed using two- and three-way ANOVA. HRR60s and cBRS were significant and similarly reduced in both groups in the occlusion compared to the control session (combined values: 20 ± 10 vs. 26 ± 9 beats min and 2.1 ± 1.2 vs. 3.2 ± 2.4 ms mmHg , respectively, P < 0.05). HRR300s and HRV were also reduced in the occlusion session, although these reductions were significantly greater in HT compared to NT (-16 ± 11 vs. -8 ± 15 beats min for HRR300s, P < 0.05). The results support the role of metaboreflex in HRR and suggest that increased metaboreflex sensitivity may partially explain the delayed HRR observed in HT men.

Reproducibility of Heart Rate Variability Indices at Post-maximal Exercise

“…To the best of our knowledge, no previous study has evaluated the reproducibility of time-varying HRV analysis after maximal exercise using passive and active recovery. Previous evidence has confirmed the clinical usefulness of post-exercise cardiac autonomic recovery assessments using both passive [4,5,29] and active [17,30] recovery. Since these conditions yield different hemodynamic responses [31], it could be hypothesized that the reproducibility of post-exercise HRV would be different between them.…”

“…The analysis of HRV in the post-exercise recovery period provides useful information about cardiac autonomic responses to physiological stress [3,5], and is able to predict cardiovascular events [4]. Although passive and active recovery yield different hemodynamic responses [5].…”

“…total mortality. This new approach seems to provide additional information about autonomic cardiac integrity [5,6], thereby improving the predictive potential of HRV.…”

“…Such discrepancies may be related to the method of signal selection, since most of the previous studies considered the average of total recovery period [7,10,11]. The time-varying of the RMSSD in segments of 30 sec is widely employed in literature [5,[15][16][17]. However, the reproducibility of RMSSD in segments of 30 sec was assessed in only one study [10].…”

Effects of postexercise cooling on heart rate recovery in normotensive and hypertensive men

“…As HT subjects present impaired autonomic responses after exercise (Greaney et al, 2014;Pec ßanha et al, 2016), any strategy that could ameliorate this response has clinical importance, promoting a likely preventive effect on acute cardiac events (Cole et al, 1999;Nishime et al, 2000). As HT subjects present impaired autonomic responses after exercise (Greaney et al, 2014;Pec ßanha et al, 2016), any strategy that could ameliorate this response has clinical importance, promoting a likely preventive effect on acute cardiac events (Cole et al, 1999;Nishime et al, 2000).…”