Your ACTN3 gene doesn’t guarantee power, but it helps explain it. Whether you carry the RARE Variant or not, fast-twitch muscle is trainable. Lift heavy, move violently, and express the speed written ...

Influencers call sprinting the ultimate fat-burning workout. Experts say it’s more nuanced—but research shows this high-intensity exercise offers surprising benefits for the heart, muscles, and even ...

Tsukuba, Japan—Muscle fibers, which constitute skeletal muscle, are classified into two main types: slow-twitch (Type I, red muscle) and fast-twitch (Type II, white muscle). Slow-twitch fibers are ...

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