fast-twitch

or fast·twitch

[ fast-twich, fahst- ]
/ ˈfæstˌtwɪtʃ, ˈfɑst- /

adjective Physiology.

of or relating to muscle fiber that contracts relatively rapidly, utilized especially in actions requiring maximum effort of short duration, as sprinting (distinguished from slow-twitch).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019