Staining of a skeletal muscle cross-section showing different types of muscle fiber in young mice. Green: slow-twitch fibers type I; Red: Intermediate fast-twitch fibers type IIA; Purple: Very ...

Muscle fiber type didn’t have any impact on how much muscle size (as measured with a full-body MRI) or strength increased. The subjects did get bigger muscles, with overall gains ranging from 3 ...

Almost one in five people lack the protein α-actinin-3 in their muscle fibers. Researchers at Karolinska Institutet in Sweden now show that more of the skeletal muscle of these individuals ...