ABSTRACT
The main physiological adaptive feature of resistance exercise training (RET) is increased muscle mass, which manifests as an increase in the dimensions of whole muscle groups as a result of growth of individual muscles. These gross physiological changes in skeletal muscle mass are most commonly determined using imaging techniques such as dual-energy X-ray absorptiometry, computed tomography, magnetic resistance imaging (MRI), or ultrasonography. In the immediate period following a single bout of resistance exercise (RE), muscle protein synthesis (MPS) is markedly increased approximately two- to fourfold above baseline rates. The magnitude of increase in MPS in response to RE displays a dose-dependent increase in MPS, reaching near maximal rates at approximately 60% of one-repetition maximum (1RM) (55), beyond which no additional stimulation is observed. Of all the signaling pathways associated with RET response, the mechanistic target of rapamycin, complex 1 is considered a “master” determinant of the regulation of RET-induced hypertrophy.
