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

Abstract

Background Postexercise heart rate recovery (HRR) is determined by cardiac autonomic restoration after exercise and is reduced in hypertension. Postexercise cooling accelerates HRR in healthy subjects, but its effects in a population with cardiac autonomic dysfunction, such as hypertensives (HT), may be blunted. This study assessed and compared the effects of postexercise cooling on HRR and cardiac autonomic regulation in HT and normotensive (NT) subjects. Methods Twenty-three never-treated HT (43 AE 8 years) and 25 NT (45 AE 8 years) men randomly underwent two exercise sessions (30 min of cycling at 70% VO 2peak ) followed by 15 min of recovery. In one randomly allocated session, a fan was turned on in front of the subject during the recovery (cooling), while in the other session, no cooling was performed (control). HRR was assessed by heart rate reductions after 60 s (HRR60s) and 300 s (HRR300s) of recovery, shortterm time constant of HRR (T30) and the time constant of the HRR after exponential fitting (HRRs). HRV was assessed using time-and frequency-domain indices.Results HRR and HRV responses in the cooling and control sessions were similar between the HT and NT. Thus, in both groups, postexercise cooling equally accelerated HRR (HRR300s = 39AE12 versus 36 AE 10 bpm, P≤0Á05) and increased postexercise HRV (lnRMSSD = 1Á8 AE 0Á7 versus 1Á6 AE 0Á7 ms, P≤0Á05). Conclusion Differently from the hypothesis, postexercise cooling produced similar improvements in HRR in HT and NT men, likely by an acceleration of cardiac parasympathetic reactivation and sympathetic withdrawal. These results suggest that postexercise cooling equally accelerates HRR in hypertensive and normotensive subjects.

Airflow rates and breathlessness recovery from submaximal exercise in healthy adults: prospective, randomised, cross-over study

“…In healthy volunteers, cool airflow from an industrial fan placed in front (~1 metre) of the participant's face during recovery following 30 minutes cycling exercise reduced heart rate recovery time (in contrast to our findings) but breathlessness measures were not taken (5), and airflow rate and direction were not reported.…”

“…In healthy individuals, cool airflow from a fan during exercise in a hot environment increases endurance time and reduces perceived exertion ratings (3). In a normothermic environment, cool facial airflow e.g., from a fan, reduces self-reported breathlessness induced by increased inspiratory load (4) and when fan-airflow is used to provide cooling after exercise, heart rate recovery is quicker (5).…”

Activation of Mechanoreflex, but not Central Command, Delays Heart Rate Recovery after Exercise in Healthy Men

“…It is also important to point out that metabolic and thermal impacts of the exercise/recovery were similar among the three sessions, as confirmed by similar BLC and T c . These aspects support that differences in HRR between the sessions and groups should not be attributed to other regulatory mechanisms such as metaboreflex [14] and/or thermoregulation [15,26].…”

“…This is a randomized crossover trial testing the effects of central command and mechanoreflex on HRR, in healthy middle-aged men. Data reported herein are derived from a larger trial that verified the effects of different neural regulatory mechanisms on HRR in healthy normotensive and hypertensive men [14,15].…”

Validation of a smart shirt for heart rate variability measurements at rest and during exercise

“…Measurements of HRV are used to monitor and supervise health and fitness outcomes and have been established in sport and exercise (Singh et al, 2018). HRV provides an objective parameter for coaches and athletes to assess and monitor several aspects: an athlete's fitness level (Djaoui et al, 2017), response to exercise (Guerra et al, 2014), adaptation to training (Plews et al, 2013), recovery status (Chen et al, 2011), overtraining (Le Meur et al, 2013) and response to environmental stressors (Peçanha et al, 2020). Training periodization based on HRV analysis can improve endurance performance effectively (Kiviniemi et al, 2010).…”