Effects of resistance exercise training on hemodynamic profile and on cardiovascular autonomic control in ovariectomized hypertensive rats

Abstract

Many studies have demonstrated that the incidence of cardiovascular disease increases significantly in postmenopausal women. Regular physical activity induces a reduction of risk factors and may reduce and/or prevent cardiovascular dysfunctions. However, these benefits have been observed mainly with the practice of dynamic aerobic physical activity, while studies involving other types of exercise are few and controversial. Thus, the objective of this study will be to investigate the effects of dynamic resistance training on hemodynamic profile and on autonomic control of heart rate in hypertensive rats submitted to ovarian hormone deprivation. Wistar rats (190-220g) will be divided into four groups (n=8 in each group): sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and trained hypertensive ovariectomized rats (THO). The ovariectomy will be performed in the animals at 10 weeks of age. After 1 week-recovery, the animals will be submitted to a maximal exercise load test. The dynamic resistance training will be prescribed between 40-60% of the maximal exercise load, obtained in the maximal test, for 8 wks (30-50 min/day; 5x/wk). After the resistance training protocol, the rats will be cannulated to record arterial pressure and direct assessment of autonomic control of heart rate (by pharmacological blockade). The results of this project may improve knowledge for efficient use of resistance training as a non-pharmacological treatment of hypertension in postmenopausal women.(AU)