A recent study confirmed the notion that Paints and Quarter Horses carry a higher proportion of Type 2B muscle fibers—the “fast twitch” fibers that contract more powerfully for sprinting and other quick movements. Research proves the variants are targets of selective breeding.


Study reveals link between selective breeding, the


“sprinting” mutation and fast-twitch muscle fibers.


Article by IRENE STAMATELAKYS Photography by JESSICA HEIN


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