Muscles of The Trunk and Pelvis Are Responsive to Testosterone

[Michael Scally MD]

Muscles of The Trunk and Pelvis Are Responsive to Testosterone Administration

Testosterone dose-dependently increases appendicular muscle mass. However, the effects of testosterone administration on the core muscles of the trunk and the pelvis have not been evaluated. The present study evaluated the effects of testosterone administration on truncal and pelvic muscles in a dose–response trial.

Participants were young healthy men aged 18–50 years participating in the 5α-Reductase (5aR) Trial. All participants received monthly injections of 7.5 mg leuprolide acetate to suppress endogenous testosterone production and weekly injections of 50, 125, 300, or 600 mg of testosterone enanthate and were randomized to receive either 2.5 mg dutasteride (5aR inhibitor) or placebo daily for 20 weeks.

Muscles of the trunk and the pelvis were measured at baseline and the end of treatment using 1.5-Tesla magnetic resonance imaging. The dose effect of testosterone on changes in the psoas major muscle area was the primary outcome; secondary outcomes included changes in paraspinal, abdominal, pelvic floor, ischiocavernosus, and obturator internus muscles. The association between changes in testosterone levels and muscle area was also assessed.

Testosterone dose-dependently increased areas of all truncal and pelvic muscles. The estimated change (95% confidence interval) of muscle area increase per 100 mg of testosterone enanthate dosage increase was 0.622 cm2 (0.394, 0.850) for psoas; 1.789 cm2 (1.317, 2.261) for paraspinal muscles, 2.530 cm2 (1.627, 3.434) for total abdominal muscles, 0.455 cm2 (0.233, 0.678) for obturator internus, and 0.082 cm2 (0.003, 0.045) for ischiocavernosus; the increase in these volumes was significantly associated with the changes in on-treatment total and free serum testosterone concentrations.

In conclusion, core muscles of the trunk and pelvis are responsive to testosterone administration. Future trials should evaluate the potential role of testosterone administration in frail men who are predisposed to falls and men with pelvic floor dysfunction.

Tapper J, Arver S, Pencina KM, et al. Muscles of the trunk and pelvis are responsive to testosterone administration: data from testosterone dose–response study in young healthy men. Andrology 2018;6:64-73. Muscles of the trunk and pelvis are responsive to testosterone administration: data from testosterone dose–response study in young healthy men

 

[Oregongearhead]

Muscles of The Trunk and Pelvis Are Responsive to Testosterone Administration

Testosterone dose-dependently increases appendicular muscle mass. However, the effects of testosterone administration on the core muscles of the trunk and the pelvis have not been evaluated. The present study evaluated the effects of testosterone administration on truncal and pelvic muscles in a dose–response trial.

Participants were young healthy men aged 18–50 years participating in the 5α-Reductase (5aR) Trial. All participants received monthly injections of 7.5 mg leuprolide acetate to suppress endogenous testosterone production and weekly injections of 50, 125, 300, or 600 mg of testosterone enanthate and were randomized to receive either 2.5 mg dutasteride (5aR inhibitor) or placebo daily for 20 weeks.

Muscles of the trunk and the pelvis were measured at baseline and the end of treatment using 1.5-Tesla magnetic resonance imaging. The dose effect of testosterone on changes in the psoas major muscle area was the primary outcome; secondary outcomes included changes in paraspinal, abdominal, pelvic floor, ischiocavernosus, and obturator internus muscles. The association between changes in testosterone levels and muscle area was also assessed.

Testosterone dose-dependently increased areas of all truncal and pelvic muscles. The estimated change (95% confidence interval) of muscle area increase per 100 mg of testosterone enanthate dosage increase was 0.622 cm2 (0.394, 0.850) for psoas; 1.789 cm2 (1.317, 2.261) for paraspinal muscles, 2.530 cm2 (1.627, 3.434) for total abdominal muscles, 0.455 cm2 (0.233, 0.678) for obturator internus, and 0.082 cm2 (0.003, 0.045) for ischiocavernosus; the increase in these volumes was significantly associated with the changes in on-treatment total and free serum testosterone concentrations.

In conclusion, core muscles of the trunk and pelvis are responsive to testosterone administration. Future trials should evaluate the potential role of testosterone administration in frail men who are predisposed to falls and men with pelvic floor dysfunction.

Tapper J, Arver S, Pencina KM, et al. Muscles of the trunk and pelvis are responsive to testosterone administration: data from testosterone dose–response study in young healthy men. Andrology 2018;6:64-73. Muscles of the trunk and pelvis are responsive to testosterone administration: data from testosterone dose–response study in young healthy men

Thats why the ladies love us , more muscle for thrusting Jackhammer pelvis !

 

[Redrum42]

I wonder the amount this is responsible for the bubble gut/"palumboism" that is so common, and so popular to talk about these days.

It seems obvious to me but rarely included in said discussions: after a certain size, you want more muscle you need more AAS. More AAS will result in more muscle everywhere, even "untrained muscles" as is evident in high level body builders. Facial muscles, tibialis anterior, etc. Therefore of course muscles of the "trunk " will too, even without considering visceral fat, organ size, etc this is probably a huge reason behind unappealing oversized guts in high level BB and PL competitors. The abs and obliques are just massive and thick.

 

[johntt44]

Those bodybuilders get the big gut from gh. The internal organs actually grow from the gh giving a distended look. If it were the muscles of the abdominal wall, the stomach would still be flat but thicker not distended.