One in five people lack protein α-actinin-3 in their muscle fiber, shows study

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 comprises slow-twitch muscle fibers, which are more durable and energy-efficient and provide better tolerance to low temperatures than fast-twitch muscle fibers.