An experimental procedure that simulates the effects of a maximal endurance training stimulus on muscle. Experiments in which a rabbit anterior tibial muscle was subjected to a continuous train of electrical pulses showed that skeletal muscle has a remarkable capacity for adaptation to the extreme metabolic demands of chronic stimulation. After 5–6 weeks of chronic stimulation, the muscle changed from containing predominantly fast fibres (about 94%) to containing only slow-twitch fibres. In addition, the muscle became significantly less fatigable and there was an increase in the number of blood capillaries per unit of muscle cross-sectional area.
Subjects: Sports and Exercise Medicine.