The Effects of VO2max on Levels of Testosterone as Males Age

Purpose: The reduction of Testosterone secretion by the gonads is “hypogonadism” and development of age-related hypogonadism is known as “late-onset hypogonadism”. Late-onset hypogonadism is characterized by issues such as osteoporosis, Alzheimer’s disease, frailty, obesity, cardiac failure and ischemic heart disease. The purpose of this investigation was to determine the impact of ⩒O2max on age-related declines in free and bound plasma testosterone levels in healthy men. Methods: A total of 45 male subjects of various ethnicities aged 20-62 years participated in this study. Resting blood samples were collected, after which subjects were on cycle ergometer. Subjects started the trail and complete four three-minute heart rate adjusted incremental stages. The ⩒O2max of each subject was estimated using a sub-maximal cycling exercise protocol. Free and Bound testosterone was then removed from blood serum samples and measured. Results: High levels of aerobic fitness did not offset age-related declines in circulating levels of free testosterone. While significant differences were found amongst the Young population (Low aerobic fitness versus High aerobic fitness) (p=0.045, F=2.912), this was not relevant to the investigation. Conclusion: After controlling for age, aerobic fitness did not prevent the age-associated decline in Testosterone. Taking the results of this study into consideration when creating countermeasures for older adult males with symptoms of hypogonadism, it is suggested that an exercise countermeasure have a combination of endurance and strength training to help mediate levels of testosterone with age.