Maximizing Mechanisms of Muscle Hypertrophy to Combat Sarcopenia in Older Adults

Resistance training has shown the most promise among interventions aimed to combat aging muscle atrophy as it enhances strength, power, and mobility function, but induces varying degrees of skeletal muscle hypertrophy as the investigators demonstrated in the initial 5-year funding period of this award (2001-2006). In the subsequent 5-year funding period (2007-2012), the investigators built on this prior work by using a dose-response approach in older adults - ultimately to optimize the treatment of age-related muscle atrophy. The investigators tested four, long-term resistance training prescriptions in older (60-75 yr) women and men to determine which prescription maximizes mechanisms driving muscle regrowth. One of the innovations in this project was the use of a 4-wk pre-training program to reach a plateau in the early, non-muscle mass adaptations, thereby establishing a true baseline from which both mechanisms of measurable muscle hypertrophy and functional consequences of hypertrophy could be studied in a tightly integrated fashion without bias in the subsequent experimental period. A randomized design was used to test the overarching hypothesis that a novel program of mixed strength and power training would optimize the anabolic environment to promote muscle hypertrophy and robust gains in performance. This hypothesis was tested with three specific aims.