1046 ng/dL Increase in Testosterone for 1.5kg Lean Body Mass in 16 Weeks
Before you read on: This was a study done on 112 men aged 65–90 years , so the results are only partly significant in view of the effects of testosterone supplementation on younger men. In a double-masked 2x3 factorial design the scientists administered testosterone gel (5g/day vs. 10g/day via Leydig cell clamp) and rhGH (0 vs. 3 vs. 5 µg/kg/d) to the subjects who had a mean baseline testosterone level of 493ng/dL. They summarize the results for the testosterone and the testosterone + rhGH groups as follows: Increases in total testosterone of 1046 ng/dL (95% confidence interval = 1040–1051) and 898 ng/dL (95% confidence interval = 892–904) were necessary to achieve median increases in lean body mass of 1.5 kg and appendicular skeletal muscle mass of 0.8 kg, respectively , which were required to significantly enhance one-repetition maximum strength (≥30%). Co-treatment with rhGH lowered the testosterone le...