Comparison of acute effects of different resistance exercise protocols with and without blood flow restriction on selected hypertrophy-related hormones in competitive wrestlers

The study aimed to compare the acute effects of low resistance exercises with partial and complete blood flow restriction (BFR) and heavy resistance exercise on growth hormone (GH), myostatin, testosterone, and cortisol in competitive wrestlers. Forty elite wrestlers were randomly divided into four groups (n=10); low resistance training with complete BFR (LRT+CBFR), low resistance training with partial BFR (LRT+PBFR), low resistance training (LRT), and heavy resistance training (HRT). Blood samples were collected before and after the intervention, and a specific ELISA kit measured variables. Analysis of covariance and paired t-test was performed to analyze the data. There were no significant differences in the variables between the four interventions. Intra-group results showed a significant decrease in myostatin levels in the HRT group (p=0.02), and a significant increase in GH in the LRT+CBFR (p=0.02) and LRT+PBFR (p=0.03), testosterone in the HRT group (p=0.04) and cortisol in the three groups LRT+CBFR (p=0.02), LRT+PBFR (p=0.01) and HRT (p=0.04). Despite the similarity of the changes in the four interventions, due to the percentage of changes, it seems that low resistance training with BFR could produce similar anabolic effects to high-intensity resistance training.