Key points are not available for this paper at this time.
T ESTOSTERONE (T) may increase skeletal muscle volumebypromotinghypertrophyofmyofibers(1). T appears to cause similar effects in younger and older men(2),highlightingthatskeletalmuscleretainsahigh degreeofplasticityevenintoolderage.Tlevelsinmen begintodecreasebyapproximately1%peryearafterthe fourthdecadeoflife(3)inparallelwiththereductionin skeletal muscle mass and strength (4). This waning of anabolicmaintenancemaybeonefactorimplicatedinthe atrophy of skeletal muscle with old age (sarcopenia). T replacement therapy may therefore delay or minimize age-related muscle atrophy, thus providing the rationale forTtherapyincombatingtheeffectsofsarcopeniaand frailty(5). Changesinmusclesizeandstructurecanbedetectedby usingultrasoundtoassessthegeometricarrangementofits fibers, termed muscle architecture (6). Muscle thickness (MT; Figure
Atkinson et al. (2010) studied this question.