Muscular training through localized in vivo electrical stimulations.

In vivo electrical stimulations were applied to the gastrocnemius muscles of intact frogs for prolonged periods which lead to improved muscular efficiency and delayed onset of fatigue. The muscular strength improvement was correlated to increased tissue contractile proteins and decreased collagen content. Elevated levels of muscular fuels, mitochondrial content, oxidative metabolism in the stimulated muscles were suggested to be responsible for the delayed onset of fatigue. In view in these characteristics regarding the improvement at physical and metabolic levels, the muscles exposed to chronic electrical stimulations were termed as trained muscles. The applicability of electrical stimulations to induce the training effects into the muscles in atrophic and dystrophic conditions to avert the muscle wastings was suggested.