Everyone is familiar, at least hand-wavingly, with the distinction between slow-twitch and fast-twitch muscle-fiber types. The former are great for running marathons; the latter are ideal for sprinting 100 meters. But how do we know in practice which kind of muscle fibers we have and what we should do with them?
A new paper in the International Journal of Sports Physiology and Performance, from a research team led by Eline Lievens of Ghent University in Belgium, poses these questions to more than 400 elite coaches and sports scientists across a wide variety of sports. Ninety percent of them believe that knowing the dominant muscle-fiber type of an athlete is useful for optimizing training and performance—but only half of them claim to actually know which of their athletes are slow-twitch or fast-twitch. A growing body of research suggests that this is a problem, or at least a missed opportunity.
On average, humans have a roughly 50-50 mix of slow- and fast-twitch fibers. But there’s huge variation around this average: some people are mostly slow-twitch, others are mostly fast-twitch. In recent years,…
