Response of testosterone and semen parameters to a 14-week aerobic training in sedentary obese men with hyperglycaemia

Introduction
Obesity, sedentarism, and insulin resistance are strongly associated with increased deoxyribonucleic acid fragmentation index (DFI) of sperms, reduced total testosterone (TT), and low semen quality, which can be prevented by lifestyle modification. This study aimed to investigate the effect of 14-week moderate-intensity aerobic exercise on serum TT, semen parameters, and DFI in centrally obese men with hyperglycaemia.

Methods
Overall, 40 men aged 26–39 years with waist circumference (WC) > 102 cm, body mass index (BMI) limited from 30 to 34.9 kg/m2, and fasting blood glucose (FBG) levels of 100–125 mg/dl were assigned to the study and control groups. The study group (n = 20) received supervised 14-week moderate-intensity aerobic exercise on a treadmill for 40 minutes, 3 times weekly, in addition to 1-hour home walking (on the alternative days of aerobic exercise), while the control group (n = 20) received general advice on increasing physical activity.

Results
In the study group, exercise significantly improved BMI, WC, FBG, serum TT, sperm DFI, and semen parameters, including motility (progressive and static) and morphology (p < 0.05), while the volume and count of semen showed no significant difference. The control group presented no significant changes.

Conclusions
The deteriorating effect of central adiposity, hyperglycaemia, and sedentarism on semen quality and nuclear damage of sperms (assessed by DFI) is prevented or counteracted by increased exercise-induced TT production, resulting from decreased BMI, FBG, and WC.