Bigger muscles, and the strength tests could not agree
Pooled trials report handgrip up 1.58 kgf and leg press up 91 newtons. Sixteen others found no handgrip effect, and the trial that added lean mass found no knee-strength gain.
What the study found
Extra muscle did not reliably become extra strength
Eleven pooled trials report handgrip up 1.58 kgf and leg press up 91 newtons; a three-year trial adds chest press up 16.3 newtons. Sixteen others found no handgrip effect and nothing musculoskeletal left at twelve months, and the trial that added lean mass found no knee-strength gain.
The caveat · Pooled from mostly null grip trials
Only one of the seven handgrip trials found a gain on its own; the pooled significance comes from combining mostly null results, over an interval running from 0.17 to 3.0 kgf. The leg-press result sits exactly at p = 0.05. Physical performance, the outcome closest to something a man would notice, did not improve, and rested on only two comparable trials.
What we don't know
Whether testosterone makes men stronger is unsettled. The pooled gains rest on mostly null trials and other studies found none, but a knee, a hand squeeze and a leg press measure different things and can disagree without any being wrong.