From the article:
Yale enrolled the largest number of participants at any one site (84 of 790) for these double-blind, placebo-controlled trials that investigated the efficacy of testosterone gel for multiple outcomes, including sexual function, physical function, and vitality.
The researchers found that men who received testosterone therapy for one year, versus those on placebo, saw significant improvements in sexual function, including sexual activity, sexual desire, and erectile function.
[…]
While participants enrolled in the trial that assessed physical function did not see significant improvements in their walking ability – as measured by an increase of 50 meters or more in their distance walked in 6 minutes – an increase was found when all study participants were evaluated. In addition, men enrolled in the vitality trial saw modest benefits in terms of improved mood and fewer depressive symptoms.
While the results were somewhat mixed, Gill noted an overall benefit that had not been seen in previous studies. “One way of interpreting the results across trials is a global impression of change,” he said. “We found that testosterone improved men’s impression that their sexual desire, walking ability, energy level, and overall health were better.”