Older men are as responsive as young men to the anabolic effects of graded doses of testosterone on the skeletal muscle.

http://www.eclips.consult.com/eclips...741(08)70456-6

http://jcem.endojournals.org/cgi/con...ll/90/2/678#T4

Older men are as responsive as young men to testosterone's anabolic effects; however, older men have lower testosterone clearance rates, higher increments in hemoglobin, and a higher frequency of adverse effects. Although substantial gains in muscle mass and strength can be realized in older men with supraphysiological testosterone doses, these high doses are associated with a high frequency of adverse effects. The best trade-off was achieved with a testosterone dose (125 mg) that was associated with high normal testosterone levels , low frequency of adverse events, and significant gains in fat-free mass and muscle strength.