Many older men take testosterone supplements in the hope of recapturing some of their youthful vigor. According to a new study, doing so won't help functional fitness in already-active older men.
The study, published in The Journal of Clinical Endocrinology & Metabolism, involved 167 men with an average age of 66 and low-normal testosterone levels. For a year, they received either transdermal testosterone or a placebo. In addition, some did resistance training over the course of the study, while others did no formal exercise.
At the end of the study, testosterone blood levels in the men who had received supplements was nearly twice that of the other men. And they had a slight increase in lean body mass, which is a common motivation for taking testosterone. But for the men who did resistance training, their functional fitness, as measured by attributes such as upper- and lower-body strength and flexibility, and tests such as climbing stairs and distance covered in a six-minute walk, didn't improve any more than that of the weight-training men who didn't take testosterone.
This study supports the idea that our bodies function as an integrated whole rather than a set of distinct systems that can be precision-targeted. While declines in testosterone levels are common with aging, they can be partly offset by regular bouts of high-intensity exercises, such as sprints, hill workouts and weight training, that spur testosterone production.