Post-exercise aerobic hypotension and its hemodynamic and neural mechanisms in pre-hypertensive subjects: time of day influence and association with circadian endocrine regulation

• Grant number: 11/03584-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2012
• End date: August 31, 2013
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Cláudia Lúcia de Moraes Forjaz
• Grantee: Leandro Campos de Brito
• Host Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Aerobic exercise is recommended for individuals with borderline values of blood pressure (BP) in order to prevent the evolution for the framework of hypertension. A single session of aerobic exercise reduces BP in the recovery period, which has been termed "post-exercise hypotension." However, for this phenomenon has important clinical need that has significant magnitude and duration. In this sense, this study will investigate the changes in post-exercise hypotension and their mechanisms derived from the time of day when exercise is performed. Previous studies have found lower post-exercise hypotension in the morning (8 am) than the afternoon (16h), but these studies did not include a control situation and assessed only a few hemodynamic determinants of this phenomenon, without investigating the neuroendocrine regulation possibly involved in this response. Thus, the objective of this study is to compare the response of the BP, its hemodynamic determinants and their neural and endocrine mechanisms after aerobic exercise in the early morning (9:00 am) and at the end of the day (19:00 hours), relating results at each stage of the day with the levels of some markers of neurohormonal circadian rhythm. To this end, 16 men, young adults pre-hypertensive participate in 4 experimental sessions, which will be performed in random order: two morning and two at the end of the day. At each stage, there will be a control session (resting) and another of exercise (cycle ergometer, 45 min, 50% VO 2peak). At the beginning of each experimental session will be collected blood samples for hormone analysis. Also, before and after the intervention, heart rate, blood pressure, cardiac output, cardiac autonomic modulation and vasomotor, baroreflex sensitivity, muscle blood flow and vascular reactivity will be measured. The BP will also be monitored following outpatient interventions for 24 hours. The results obtained in four sessions will be compared by three factors ANOVA for repeated samples, the main factors the phase of the day (morning and late in the day), the session (control and exercise) and stage (pre-and post-intervention). P values <0.05 are accepted as significant and, when necessary, the test will be used for post hoc Newman-Keuls. (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BRITO, LEANDRO; PECANHA, TIAGO; TINUCCI, TAIS; SILVA-JUNIOR, NATAN; COSTA, LUIZ; FORJAZ, CLAUDIA. Time of day affects heart rate recovery and variability after maximal exercise in pre-hypertensive men. CHRONOBIOLOGY INTERNATIONAL, v. 32, n. 10, p. 1385-1390, 2015. (13/05519-4, 11/03584-8, 13/04997-0)

L.C. BRITO; A.C.C. QUEIROZ; C.L.M. FORJAZ. Influence of population and exercise protocol characteristics on hemodynamic determinants of post-aerobic exercise hypotension. Brazilian Journal of Medical and Biological Research, v. 47, n. 8, p. 626-636, 2014-06-24. (11/03584-8, 09/18219-3)

BRITO, LEANDRO C.; REZENDE, RAFAEL A.; MENDES, CAROLINE; SILVA-JUNIOR, NATAN D.; TINUCCI, TAIS; CIPOLLA-NETO, JOSE; DE MORAES FORJAZ, CLAUDIA L.. Separate aftereffects of morning and evening exercise on ambulatory blood pressure in prehypertensive men. JOURNAL OF SPORTS MEDICINE AND PHYSICAL FITNESS, v. 58, n. 1-2, p. 157-163, JAN-FEB 2018. (11/03584-8)

DE BRITO, LEANDRO C.; REZENDE, RAFAEL A.; DA SILVA JUNIOR, NATAN D.; TINUCCI, TAIS; CASARINI, DULCE E.; CIPOLLA-NETO, JOSE; FORJAZ, CLAUDIA L. M.. Post-Exercise Hypotension and Its Mechanisms Differ after Morning and Evening Exercise: A Randomized Crossover Study. PLoS One, v. 10, n. 7, JUL 17 2015. (11/03584-8)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

BRITO, Leandro Campos de. Postexercise aerobic hypotension and it hemodynamic and neural mechanisms in pre-hypertensive men: time of day influence and correlation with endocrine circadian regulation. 2013. Master's Dissertation - Universidade de São Paulo (USP). Escola de Educação Física e Esportes (EEFE/BT) São Paulo.