The effect of circuit resistance training with different intensities on the agouti-related protein, insulin and glucose plasma levels in young men

Agouti-related protein (AgRP) is a signaling peptide that affects feeding behavior, energy homeostasis, and the stimulation of the hypothalamic–pituitary–adrenal axis. The aim of the present study was to investigate the effect of a 6-week circuit-resistance training course (10 exercises at 20%, 40%, 60%, and 80% of 1RM) at different intensities on the levels of plasma AgRP, plasma insulin, and glucose. The participants in this experimental study included 45 dormitory male students, aged 20-24 years, with the mean weight of 70.61±3.76 kg, mean age of 21.55±0.17 years, and mean height of 174.84±1.15 cm. They were randomly divided into five groups, each with nine members (i.e., one control group and four experimental groups at 20%, 40%, 60%, and 80% of 1RM). The experimental groups performed the circuit-resistance training exercises at the specified intensities; in contrast, the control group performed no regular training during the course of the study. The blood samples were collected from the venous vein 48 hours before and after the training session (three hours after normal breakfast). The results showed no significant differences between the groups in terms of the AgRP (P=0.399) and glucose levels (P=0.270); however, the difference related to the insulin levels was observed to be significant (P=0.013). According to the results of this study, a larger reduction in the AgRP levels is associated with high intensities of resistance training (i.e., at 80% of 1RM). Therefore, training intensity could be regarded as an influential factor in reducing the appetite and controlling obesity among young men