For men who have low testosterone, exercise alone probably won’t raise their levels enough to make a difference in how they feel, says endocrinologist Scott Isaacs, MD, of Emory University. Doctors and fitness professionals still have a lot to learn about exercise and its effects on testosterone. Research suggests that excessive alcohol consumption can decrease testosterone levels. Knowing the impacts of T treatment and exercise on variables such as body composition, strength and aerobic fitness extends our understanding of the relative benefits of physiological and pharmacological interventions in aging men. If improvement in lean body mass is the primary aim, then T treatment could be considered, and the combination of T and exercise may be more beneficial than either in isolation. Healthy testosterone levels help the body use fat as a fuel source, particularly during periods of caloric deficit or intense physical activity. In addition to the fatigue, I had no interest in sex for days, or even weeks on end. I’m training for the IRONMAN World Championship after all. I grab my bag full of sweaty training gear from that morning's threshold ride and stand up. Whether this effect is secondary to weight loss and less aromatization, or solely secondary to exercise, is unclear. On the other hand, Wilkinson et al. observed significant gains in strength and hypertrophy in the absence of any measurable changes in F-Testo and insulin growth factor 1. In contrast, other studies of T treatment alone (i.e. no exercise intervention) have reported improvements in strength 35, 48, 52, 57, 59, 98, 114, 115. Some evidence suggests that additive effects for lean body mass may be more apparent in younger men, but that gains in strength may be less age-dependent, possibly due to neural benefits. It is therefore of interest in our TEX study, that despite a much lower (physiological) T dose delivered in older participants, we observed improvements in lean body mass. Finally, it has been reported that increases in skeletal muscle mass as a result of T treatment may be dose-dependent 50, 52, 56, 94, 95. If improvement in lean body mass is the primary aim, then T supplementation could be considered, and the combination of T and exercise may be more beneficial than either in isolation (Figs. 1 and 2). So unless you’re training for the Marathon of Mediocrity, consider swapping out some long runs for explosive, strength-based circuits. Excessive endurance exercise—yes, that daily 10K—may suppress testosterone over time. Resistance training, especially heavy compound movements like squats and deadlifts, has been shown to stimulate acute testosterone spikes.
