Exercise plays a protective and preventive role against heart disease by reducing risk factors. The aim of the present study was to investigate the effect of a period of resistance training by muscle endurance method on blood pressure, heart rate and plasma endothelin 1 levels of inactive healthy men.

In this quasi-experimental study, 30 middle-aged men (mean age 47.03±  2.12 years, height 172.90 ± 3 cm, weight 80.70 ± 3.1 kg, body mass index 47.47 ± 3.66 27 kg / m2 and waist to pelvis ratio (0.98 ± 1.27) were purposefully selected and randomly divided into two groups of 15 control and experimental. The experimental group performed 8 weeks of resistance training, three sessions per week with an intensity of 40 to 70% of a maximum repetition. Before and after 8 weeks of exercise, plasma endothelin-1, systolic and diastolic blood pressure and resting heart rate were measured. Correlated t-test was used to examine intragroup changes and independent t-test was used for intergroup differences. Significance level was considered less than 0.05.

The results of this study showed that 8 weeks of muscular endurance resistance training significantly reduced the plasma endothelin level of inactive middle-aged men (P = 0.002). Also, 8 weeks of resistance training caused a significant decrease in systolic blood pressure (P = 0.001) and resting heart rate (P = 0.01) in middle-aged men, but the decrease in diastolic blood pressure was not significant (P = 0.0411).

According to the results of the present study, muscular endurance resistance training by reducing plasma endothelin-1 levels, systolic blood pressure and resting heart rate can reduce the risk of hypertension and heart disease in healthy middle-aged men as a preventive factor.