Testosterone therapy induces molecular programming augmenting physiological adaptations to resistance exercise in...

Area of Science:

• Gerontology
• Exercise Physiology
• Endocrinology

Background:

• Andropause is linked to decreased testosterone, muscle loss (sarcopenia), and frailty in aging men.
• Anabolic steroid therapies and resistance exercise training (RET) are interventions to combat sarcopenia.
• The combined effects of testosterone (T) therapy and short-term RET on muscle mass and function are not well understood.

Purpose of the Study:

• To investigate the efficacy of testosterone therapy as an adjunct to resistance exercise training in older men.
• To determine the physiological and molecular impacts of combined testosterone and RET interventions on skeletal muscle.

Main Methods:

• Eighteen healthy older men (65-75 years) received either placebo or testosterone injections biweekly for six weeks.
• Participants underwent a whole-body resistance exercise training (RET) program.
• Muscle mass, architecture, strength, and molecular markers of muscle protein synthesis and breakdown were assessed.

Main Results:

• Testosterone therapy combined with RET significantly increased fat-free mass and decreased fat mass compared to placebo.
• Muscle thickness, fascicle length, and strength gains were greater in the testosterone group.
• Testosterone therapy upregulated muscle protein synthesis, ribosomal biogenesis, and anabolic signaling pathways.

Conclusions:

• Testosterone therapy alongside RET effectively enhanced skeletal muscle mass and performance in older men.
• The intervention upregulated muscle gene expression, translational efficiency, and protein accretion.
• Combined testosterone and RET is a potent short-term strategy for improving muscle mass and function in aging men.