Does 12-weeks of exercise training reduce the risk of infertility in obese femals? A pilot study

Obese females face a number of health challenges, including infertility. Obese females are three times more likely to present with infertility compared to normal weight females. Exercise improves infertility by interacting with hormones specific to reproduction. The hormones leptin and kisspeptin (KiSS) are crucial for reproduction. Research suggests leptin may increase production and secretion of KiSS. KiSS subsequently increases gonadotropin-releasing hormone, activating the menstrual cycle and reproduction. Interestingly, circulating levels of leptin and KiSS are altered in the obese state. Leptin levels significantly increase, whereas KiSS levels decrease. Studies demonstrate increases in leptin cause leptin resistances, which is followed by a decrease in KiSS mRNA concentrations. Exercise is associated with decreases in circulating leptin and infertility, however there is no research examining the changes in KiSS after an exercise intervention. Therefore the purpose of this research was to examine the effects of an exercise intervention on circulating KiSS and leptin levels in obese females. Ten obese females were randomized to an exercise intervention (n=5) or a non-exercise control group (n=5). The exercise intervention group completed a 12-week supervised, progressive, aerobic exercise program that involved walking a treadmill between 65 – 75% of their predicated maximum heart rate. The non-exercise control group maintained their current lifestyle habits. All participants had blood drawn at three different time points; baseline, mid-point and end-point; and KiSS and leptin levels were analyzed. The exercise group had a significant decrease in %BF (p<0.01) compared to the control group from baseline to end-point testing, whereas there was a significant increase in weight (p<0.01) and BMI (p<0.01) in the control group from baseline to mid-point testing. A group main effect for circulating leptin levels was found (p<0.01), however a pairwise comparison between the exercise and control group was not significant (p=0.81). For KiSS there was a main effect of time (p