With a single molecular switch, scientists increased muscle endurance in mice a degree currently only achievable through high-intensity training.

In treated mice, easily fatigued “fast twitch” muscle fibers (Type II) became high-endurance “slow twitch” fibers (Type I).

The switch responsible is a gene called PGC-1, and the results of the study, published in the August 15 issue of the journal Nature, could spur the development of treatments that give weak patients muscular endurance.
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