The research team compared 16 normal weight men to 28 overweight/obese men. None of the men were regular exercisers. At baseline, the overweight/obese men had significantly lower total, free and bioavailable testosterone level than normal weight men. All of the study volunteers completed a 12-week aerobic exercise plan that entailed 40-60 minutes of walking or jogging on one to three days per week. Testosterone levels were also recorded at the end of the study. While their testosterone was still at lower levels than the normal weight men at baseline, overweight and obese men saw a significant increase in all measured testosterone levels. This effect was particularly evident among the men who exercised vigorously. However, the exercise intervention had no significant effect on testosterone levels in the normal weight men.
