The Effect of Low- Intensity Resistance Training with Blood Flow Restriction on Serum Cortisol and Testosterone Levels in Young Men

Based on the research evidence, the efficiency of resistance exercises depends on the changes in the hormones level to improve the muscle strength and mass. This study aimed to investigate the effect of a short course blood flow restricted resistance training on serum cortisol and testosterone levels in young men. A total of 30 healthy young men (aged 19 - 24 years) were volunteered for this study. Subjects were randomly assigned into three groups: low-intensity blood flow restricted (LIBFR) (n = 15) resistance exercise group (3 sets of 15 repetitions at 20% of 1RM (one repetition maximum)), traditional high-intensity without blood flow restriction (HIWBFR) (n = 12) resistance exercise group (3 sets of 10 repetitions at 80% of 1RM), and a control group (n = 13). Both LIBFR and HIWBFR groups trained for front leg and squat exercises 3 days per week for 3 weeks. Fasting growth hormone cortisol and testosterone levels were measured in the morning before and after exercise sessions. Data were analyzed with paired t-test and One-way ANOVA at the significant level of P < 0.05. Serum cortisol level significantly increased after the exercise for both protocols compared to baseline (P < 0.05). After 3 weeks, serum cortisol level increased significantly in LIBFR and HIWBFR groups compared to control group (P < 0.001). At the end of the exercise protocols, serum testosterone level was higher in LIBFR group compared to HIWBFR group; however, this difference was not significant (P ˃ 0.49). Short term blood flow restriction (BFR) exercise stimulates cortisol hormones production in young men. However, this program seems too short to express any difference in testosterone change. Generally, it can be concluded that low-intensity resistance training can increase short-term BFR catabolic-anabolic hormones in young men.