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

Author(s)

Pecanha, Tiago ^[1] ; Low, David ^[2] ; de Brito, Leandro Campos ^[1] ; Fecchio, Rafael Yokoyama ^[1] ; de Sousa, Patricia Nascimento ^[1] ; da Silva-Junior, Natan Daniel ^[1] ; de Abreu, Andrea Pio ^[3] ; da Silva, Giovanio Vieira ^[3] ; Mion-Junior, Decio ^[3] ; Forjaz, Claudia Lucia de Moraes ^[1]

Affiliation

^[1] Univ Sao Paulo, Exercise Hemodynam Lab, Sch Phys Educ & Sport, Ave Prof Mello Moraes 65, BR-05508030 Sao Paulo - Brazil

^[2] Liverpool John Moores Univ, Res Inst Sport & Exercise Sci, Liverpool, Merseyside - England

^[3] Univ Sao Paulo, Hypertens Unit, Gen Hosp, Sao Paulo - Brazil

• Document type: Journal article
• Source: CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING; v. 40, n. 2 DEC 2019.
• Web of Science Citations: 0

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 +/- 8 years) and 25 NT (45 +/- 8 years) men randomly underwent two exercise sessions (30 min of cycling at 70% VO2peak) 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, short-term time constant of HRR (T30) and the time constant of the HRR after exponential fitting (HRR tau). 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 = 39 +/- 12 versus 36 +/- 10 bpm, P <= 0 center dot 05) and increased postexercise HRV (lnRMSSD = 1 center dot 8 +/- 0 center dot 7 versus 1 center dot 6 +/- 0 center dot 7 ms, P <= 0 center dot 05). 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. (AU)

• FAPESP's process: 15/15466-0 - Post-exercise heart rate recovery: influence of thermoregulation
• Grantee: Tiago Peçanha de Oliveira
• Support type: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/04997-0 - Heart rate recovery after exercise: regulatory mechanisms
• Grantee: Cláudia Lúcia de Moraes Forjaz
• Support type: Regular Research Grants
• FAPESP's process: 13/05519-4 - Heart rate recovery after exercise: regulatory mechanisms in normotensives and hypertensives
• Grantee: Tiago Peçanha de Oliveira
• Support type: Scholarships in Brazil - Doctorate