Objective To investigate the changes in serum growth hormone (GH), testosterone, and insulin-like growth factor 1 (IGF-1) during low-intensity resistance exercise under different cuff pressures. Methods We performed a single-blind, cross-over design study. Twenty-five healthy young men performed three exercise protocols as follows: 1) no blood flow restriction exercise (control group), 2) resistance exercise at 40% of arterial occlusion pressure (AOP) (low group), and 3) resistance exercise at 70% of AOP (high group). Blood lactate, GH, testosterone, and IGF-1 levels were measured at four time points. Results There were no differences in the indices before exercise. The blood flow restriction exercise under different pressures had different effects on each index and there was an interactive effect. GH levels were significantly higher in the high group than in the other groups after exercise. Immediately after exercise, IGF-1 and testosterone levels were significantly higher in the high group than in the other groups. At 15 minutes after exercise, testosterone levels were significantly higher in the high group than in the other groups. Conclusions Low-intensity resistance exercise combined with blood flow restriction effectively increases GH, IGF-1, and testosterone levels in young men. Increasing the cuff pressure results in greater levels of hormone secretion.

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