Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength  in middle-aged and older men , particularly in the lower extremities
BACKGROUND Inconsistent fat-free mass ( FFM ) and muscle strength responses have been reported in r and omized clinical trials ( RCTs ) administering  testosterone replacement therapy ( TRT ) to middle-aged and older men .
Our objective was to conduct a meta- analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route .
Mechanical muscle function and lean body mass during supervised strength training and testosterone therapy in aging men with low-normal testosterone levels.
OBJECTIVES To examine the effect of strength training and testosterone therapy on mechanical muscle function and lean body mass ( LBM ) in aging men with low-normal testosterone levels in a r and omized , double-blind , placebo-controlled 24-week study . DESIGN R and omized , double-blind , placebo-controlled . SETTING Odense , Denmark . PARTICIPANTS Men aged 60 to 78 , with bioavailable testosterone levels of less than 7.3 nmol/L and a waist circumference greater than 94 cm were r and omized to testosterone  ( 50 - 100 mg/d , n = 22 ) placebo ( n = 23 ) or strength training  ( n = 23 ) for 24 weeks . The strength training group was r and omized to addition of testosterone or placebo after 12 weeks . Subjects performed supervised strength training ( 2 - 3 sets with 6- to 10-repetition maximum loads , 3 times per week ) . MEASUREMENTS Testosterone levels , maximal voluntary contraction and rate of force development , and LBM were obtained at 0 and at Weeks 12 and 24 of the intervention . RESULTS No changes in any variables were recorded with placebo . In the strength training group , maximal voluntary contraction increased 8 % after 12 weeks ( P = .005 ) . During the following 12 weeks of strength training rate of force development increased by 10 % ( P = .04 ) and maximal voluntary contraction further increased ( P < .001 ) . Mechanical muscle function was unchanged in men receiving only testosterone for 24 weeks . LBM increased only in men receiving testosterone ( P = .004 ) . CONCLUSION Strength training in aging men with low-normal testosterone levels may improve mechanical muscle function , but this effect occurs without a significant increase in LBM . Clinical ly , only the combination of testosterone therapy and strength training result ed in an increase in mechanical muscle function and LBM
Intramuscular TRT is more effective than transdermal formulations at increasing LBM and improving muscle strength  in middle-aged and older men , particularly in the lower extremities
BACKGROUND Inconsistent fat-free mass ( FFM ) and muscle strength responses have been reported in r and omized clinical trials ( RCTs ) administering  testosterone replacement therapy ( TRT ) to middle-aged and older men .
Our objective was to conduct a meta- analysis to determine whether TRT improves FFM and muscle strength in middle-aged and older men and whether the muscular responses vary by TRT administration route .