Effects of Circuit Resistance Training Intensity on the Plasma Ghrelin to Obestatin Ratios in Healthy Young Women

BACKGROUND Ghrelin and obestatin are orexigenic and anorexigenic peptides, respectively. It appears that an accurate balance between theses peptides is important for regulating energy homeostasis and body weight. OBJECTIVES The aim of this study was to identify the possible mechanisms by which circuit resistance training influences energy homeostasis and weight control. PATIENTS AND METHODS Twenty-seven female students with the mean age of 22 ± 1.54 years and mean body mass index (BMI) of 20.76 ± 1.86 kg/m(2) were selected and randomly divided into experimental and control groups. Subjects performed circuit resistance training with 40% and 80% of 1 repetition maximum (1RM) for 4 weeks. Total plasma ghrelin, obestatin, and glucose levels and the ghrelin to obestatin ratio were measured for all subjects before and after training. RESULTS One-way ANOVA tests showed that, the plasma ghrelin to obestatin ratio increased significantly in the 80% 1RM group (P < 0.05). Furthermore, a significant reduction of the plasma obestatin level was found in this group (P < 0.05). CONCLUSIONS It appears that an energy deficit caused by circuit resistance training in 80% of the 1RM group resulted in the ghrelin precursor being increasingly used for ghrelin production. Thus, obestatin secretion decreased and the ghrelin to obestatin ratio increased in order to stimulate food intake and lost energy resource consumption to eventually restore the energy balance in the body.