Assessment Of Various Intensities Of Short Term Exercise On Blood Pressure And Reaction Time In Healthy Young Adults – An Experimental Study

摘要

The purpose of this study is to investigate the effect of various intensities of short term exercise on blood pressure and reaction time. Fifty six normotensive subjects participated in the study. The participants were randomized into two exercise groups, one exercising at 40% of heart rate reserve and another exercising at 70% of heart rate reserve. Resting blood pressure and post-exercise blood pressure at 0, 10, 20, and 30 minutes, as well as pre-and post-exercise reaction time were taken. 2 sessions of aerobic exercise were performed and mean result calculated. Systolic blood pressure shows significant decrease starting from 10 minutes until 30 minutes post-exercise as compared to resting systolic blood pressure in both exercise groups. Diastolic blood pressure and mean arterial pressure decreased significantly starting at 10 minutes post-exercise in the group with 40% exercise intensity and starting at 20 minutes in the group with 70% exercise intensity. Our results also showed that there was no significant decrease in post-exercise systolic, diastolic blood pressure and mean arterial pressure between both groups with 40% and 70% intensities of exercise. Also, our study results revealed that reaction time does not differ significantly before and after a single bout of acute exercise at 40% and 70% of heart rate reserve. In conclusion, level of intensity of a single-bout of exercise does not affect the amount of post-exercise hypotension, nor does a single-bout of exercise influence the reaction time of the subjects. INTRODUCTION Aerobic exercise is currently being promoted as a lifestyle modification that lowers resting blood pressure, especially in persons with elevated levels.1 The Sixth Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure2, as well as the 1999 World Health Organization Guidelines for the Management of Hypertension3, recommended aerobic exercise as a non-pharmacological method of lowering resting blood pressure in adults.Post-exercise hypotension (PEH) is characterized by a blood pressure (BP) value that is lower than the pre-exercise value that persists for minutes or hours after an exercise session.4 The optimum intensity of exercise required to achieve a desirable reduction in blood pressure has yet to be defined, as results of various studies were inconsistent.5,6,7,8 The American College of Sports Medicine recommends the intensity of training of 55/65%–90% of maximum heart rate (HRmax) for cardiovascular fitness.9 However, it is unknown whether this level of moderate to high intensity of exercise is needed as per lowering blood pressure is concerned.Reaction time (RT) is the elapsed time between the presentation of a sensory stimulus and the subsequent behavioural response.10 Studies on humans and animals showed that aerobic exercise could improve some aspects of cognition and mental working capacity.11,12 Many studies have concluded that during exercise, reaction time is shorten.13,14,15 Few studies have concluded that reaction time pre- and post-exercise are not significantly different.16The objective of this experimental study is to assess the effect of various intensities of short term exercise on blood pressure and reaction time. We hypothesized that the rate of blood pressure decline may be associated with the different intensities of exercise. We also hypothesized that exercise in different intensities affects reaction time post-exercise. METHODOLOGY Study designStudy was done in Melaka-Manipal Medical College (MMMC) from January 2013 to February 2013. A parallel randomized controlled trial design was used. The MMMC Research Ethics Committee approved the study protocol and written informed consent was obtained from all participants. The confidentiality and autonomy of the participants was maintained.SubjectsA total of fifty-six subjects between the ages of 21-25 years participated in this study. The subjects were chosen from th