Razi Journal of Medical Sciences

Background & Aims: Today, high blood pressure is recognized as one of the main risk factors for the development of heart disease in the world and has caused many deaths in the global community (1). Numerous studies have shown that moderate reduction in blood pressure as a result of medication, physical activity, weight loss, etc. reduce the risk of cardiovascular disease (3, 4). Among the various methods of treatment today, regular physical activity and exercise have been widely supported by medical and sportswear. This support is due to the existence of valid epidemiological and clinical evidence based on the fact that various physical activities and exercise by reducing cardiovascular risk factors reduce atherogenic processes and the prevalence of various cardiovascular diseases, especially Coronary heart disease (5). But what exercise? How severe? And how long it has the greatest impact on blood pressure and cardiovascular risk factors is a question that has attracted the minds of researchers and in this regard, the effect of different training methods has been studied in different ways and conflicting results have been obtained Is. But one of the training methods that has been considered for a long time is resistance training. The best training method to increase lean mass is to increase muscle strength and endurance (8). But the proper intensity of these exercises is still debated and the results are contradictory. For this reason, researchers are looking at how intense resistance activity can have the best effect on improving blood pressure, in fact, which intensity of exercise (equal to the volume of exercise) can provide the best benefits for people with high blood pressure. Have blood.
Methods: For the present applied and quasi-experimental research, among healthy men with a history of resistance training and in the age range of 20 to 35 years, 24 eligible volunteers participated as a sample and were randomly divided into two groups (control 12 and experimental 12). Were divided. The method of conducting the research was that the researcher first explained the purpose and method of conducting the research to the subjects and after completing the consent form by the subjects, their height, weight and body fat percentage were measured. Then, before the start of training, systolic, diastolic and mean blood pressure were recorded. In order to control the effects of diet on blood pressure, subjects were asked to eat the same breakfast on the day of the test and not to do strenuous exercise for 24 hours before the test. Then, in order to perform the exercises, 1RM of the subjects was calculated using trial and error method. Then, to perform 3 training sessions, the subjects went to the club at 9:00 AM with a standard breakfast with an interval of 1 hour, and after 20 minutes of rest in a sitting position (movements: barbell chest press, front thigh press, shoulder press The barbell and the back of the machine thigh, the barbell standing front arm, the back of the barbed wire with the rope, the foot press of the machine and the kick from the front of the open hand) were performed with the desired intensity and 2 minutes rest period between sets and movements. In addition, in all movements during the eccentric and concentric contraction, the necessary control was performed to perform the movement. There was also a 72-hour interval between each exercise session. Immediately after the last set, and after that, for every 10 minutes and for 60 minutes, the subjects 'blood pressure was measured using a Citizen barometer model' CH_452 and another barometer model Scian LD-581. Mean blood pressure and heart rate were recorded as criteria. The control group was also present at the club during the protocol, which measured blood pressure and heart rate at the same time as the other subjects. Finally, descriptive statistics, Shapiro-Wilk tests, multivariate analysis of variance with repeated measures and Bonferroni post hoc at a significance level of 0.05 were used to analyze the data using SPSS 2017 software.
Results: Regarding systolic blood pressure, the results of the present study showed that regardless of severity, there was no significant difference in systolic blood pressure between the experimental groups, no significant difference was observed between and within the control groups, also between the experimental and control groups. In general, a significant difference was observed (p = 0.001). At all intensities, there is no significant difference between systolic blood pressure before and immediately after exercise. Although in all 3 systolic blood pressure intensities 60 minutes of recovery decreased compared to before exercise, but in 60% intensity of blood pressure 40, 30, 20, 10 after exercise compared to before exercise was observed significantly, in 80 Although there was a significant decrease in blood pressure after exercise only at 30 and 40 times compared to before exercise, and at an intensity of 70%, systolic blood pressure decreased significantly up to 50 minutes after exercise compared to before exercise. Showed Dari (Figures 1 and 2).

Another finding of the present study showed that there was no significant difference in diastolic blood pressure between the experimental groups, regardless of intensity, and time-to-time comparisons showed differences only in intensity of 60 and 80% and at 50 minutes after exercise (P = 0.049). No significant difference was observed between and within the control group. Also, no significant difference was observed between the experimental group and the control group in general (P = 0.56). At 70 and 80% intensity, diastolic blood pressure immediately after exercise, 50, 40, 30, 20, 10 minutes after exercise had a significant decrease compared to before exercise (p <0.05), but at 60% intensity, blood pressure difference was significant. Pre-workout diastole was significant only up to 40 minutes after exercise (p <0.05). Regarding moderate blood pressure, the results of repeated analysis of variance test showed that there was no significant difference between the mean blood pressure in general, regardless of the severity. There was a significant difference between the mean blood pressure in the experimental group and the control group in general (P =0.009), there is no significant difference between and within the control groups. Also at 70 and 80 intensities between moderate blood pressure, 40, 30, 20, 10 and 50 minutes after training compared to before training was observed a significant decrease (p <0.05), but at 60% intensity a significant decrease between Blood pressure was observed before training with 40, 30, 20 minutes after training (p <0.05).

Conclusion: The results of the present study are consistent with the results of the research of Figueroido et al. (2015) who showed a decrease in blood pressure after resistance training. In another study in the same field and in line with the findings of the present study by Figueroido et al. (2015), the effect of load intensity on hypotension after exercise and heart rate change after a strength training session and reduce systolic and diastolic blood pressure Reported (20, 23). However, inconsistent with the findings of the present study, Neri et al. (2010) showed that intra-arterial blood pressure is different in people with high blood pressure during exercise with high and low resistance. In another study inconsistent with the findings of the present study, Lamote et al. (2005) investigated the effect of different methods of resistance training on blood pressure and heart rate in heart patients and showed that between different methods of resistance training, endurance and combination on blood pressure. There is a significant difference (26,27). The reason for this difference could be that in this study, people with underlying diseases such as hypertension and heart disease were used, but in the present study, healthy people with a history of exercise participated. There was also no change in blood pressure within and between control groups, indicating that being in a sports environment and prevailing conditions such as coronary stress are not the cause of changes in blood pressure, heart rate and other factors.