[Effects of circuit resistance training on plasma ghrelin levels in young women]

ABSTRACT

Ghrelin, an orexigenic peptide secreted from stomach mucosa, affects feeding behavior and plays an important role in energy balance and glucose homeostasis. Ample evidence indicates that resistance exercise is a key component of exercise recommendations for weight control. The purpose of the current study was to determine the effects of resistance training [4 weeks] on resting levels of plasma ghrelin, glucose, insulin and estrogen. Twenty-seven female college students, aged 221 +/- 1.54 years, height 162.66 +/- 5.05 cm, BMI 20.76 +/- 1.86 kg/m[2] and fat percent 20.95 +/- 2.08% [means +/- SE] were randomized into two, the experimental [40% and 80% 1RM] and the control groups. Subjects performed circuit-resistance exercise protocol with 40% and 80% 1RM, 4 d/wk for 4 weeks. Blood samples were collected 24 hours before and 48 hours after the training program. One-way ANOVA revealed that although no significant differences were observed in circulating levels of plasma total ghrelin [P=0.88], glucose [P=0.1] and insulin [P=0.66] in the experimental group when compared to the control group, a significant negative correlation [R=-0.4, P=0.05] was found between plasma estrogen and total ghrelin levels. It seems that because of a non significant increase in plasma ghrelin levels in the present study, there was no weight change of subjects during the training program and the short duration of the training program. However, the total ghrelin sub-fractions, acylated and non acylated, may have changed