The Effects of Interval and Traditional Resistance Exercise on Hormonal Control of Adipose-tissue Lipolysis in Healthy Young Men

Abstract

Purpose: Lipolysis is regulated by lipolytic hormones, like insulin, cortisol, growth Hormone (GH), and catecholamines. Unregulated lipolysis results in the accumulation of free fatty acids (FFAs), leading to dysfunction of cells and death. Thus, the main aim of this study was to determine the effects of interval and traditional resistance exercise on hormonal control of adipose-tissue lipolysis in healthy young men. Methods: Twelve healthy males (Mean ± SD; age, 25.5 ± 3.1 years; Body mass index, 24.2 ± 2.0 kg/m2) performed tradition resistance exercise (TRE) at 80% of 1RM (3 sets of 6 repetitions) with 2 min passive recovery, and an interval resistance exercise (IRE) trial at 60% of 1RM (3 sets of 6 repetitions) followed by active recovery (1 set of 6 repetitions at 20% of 1RM). Three blood samples were taken before and immediately after exercise, and after one-hour recovery and were analyzed to measure epinephrine, norepinephrine, cortisol, and GH. Results: Statistical analyses of the data revealed that concentrations of cortisol and GH increased in response to resistance exercise and significantly decreased (p < 0.05) during the recovery period. Although there were no significant differences between the two protocols for cortisol concentration, GH increases following IRE were profoundly higher than TRE protocol. Epinephrine and norepinephrine increased (p < 0.05) in response to both resistance exercise trials, though, no between-group differences were found for these variables. Conclusion: The results of our study showed increases in GH, cortisol, epinephrine, and norepinephrine in two resistance exercise protocols which may lead to increases in fat oxidation.