Does Human Skeletal Muscle Possess an Epigenetic Memory of Testosterone?

This project's primary aim of this double-blinded, randomised, placebo-controlled trial is to investigate whether short-term testosterone administration +/- resistance exercise training induces a muscle memory response that can lead to longer-lasting benefits in aged human skeletal muscle. The investigators will provide older men with the anabolic hormone, testosterone or placebo, with or without resistance training, followed by a period of testosterone abstinence and detraining, followed by a subsequent repeated period of resistance training (retraining). This will help determine if earlier encounters with short-term testosterone administration can be "remembered" and if adaptation to later retraining can be enhanced as a consequence of encountering testosterone earlier.