Testosterone and exercise: Effects on fitness, body composition, and strength in middle-to-older aged men with low-normal serum testosterone levels

As men age, serum testosterone (T) concentrations decrease, as do fitness, strength, and lean mass. Whether testosterone treatment confers additive benefit to reverse these changes when combined with exercise training in middle-to-older aged men remains unclear. We assessed the effects of T treatment and exercise, alone and in combination, on aerobic capacity (V O2peak), body composition, and muscular strength in men 50-70 yr, waist circumference ≥95 cm and low-normal serum T (6-14 nmol L_1). Participants (n = 80) were randomized to AndroForte5 (testosterone 5.0% wt/vol, 100mg/2mL) cream (T), or matching placebo (P), applied transdermally daily, and supervised center-based exercise (Ex) or no additional exercise (NEx), for 12-wk. Exercise increased V O2peak and strength versus nonexercise (V O2peak: T + Ex: +2.5 mL kg-1 min-1, P + Ex: +3.2mL kg-1 min-1, P <0.001; leg press: T + Ex: +31 kg, P + Ex: +24 kg, P = 0.006). T treatment did not affect V- O2peak or strength. Exercise decreased total (T + Ex: -1.7, P + Ex: -2.3 kg, P <0.001) and visceral fat (T + Ex: -0.1 kg, P + Ex: -0.3 kg, P = 0.003), and increased total (T + Ex: +1.4 kg, P + Ex: +0.7 kg, P = 0.008) and arm lean mass (T + Ex: +0.5 kg, P + Ex: +0.3 kg, P = 0.024). T treatment did not affect total or visceral fat, but increased total (T + Ex: +1.4 kg, T + NEx: +0.7 kg, P = 0.015), leg (T + Ex: +0.3 kg, T + NEx: +0.2 kg, P = 0.024), and arm lean mass (T + Ex: +0.5 kg, T + NEx: +0.2 kg, P = 0.046). T + Ex increased arm lean mass (T + Ex: +0.5 kg vs. P + NEx: -0.0kg, P = 0.001) and leg strength (T + Ex: +31 kg vs. P + NEx: +12 kg, P = 0.032) compared with P + NEx, with no other additive effects. Exercise training was more effective than T treatment in increasing aerobic capacity and decreasing total and visceral fat mass. T treatment at therapeutic doses increased lean mass but conferred limited additional benefit when combined with exercise. Exercise should be evaluated as an antiaging intervention in preference to testosterone treatment in men.