Adjectives

(s)fibrous, sinewy, stringy, unchewable(of meat) full of sinews; especially impossible to chew
(a)tendinous, sinewyconsisting of tendons or resembling a tendon
(s)brawny, hefty, muscular, powerful, sinewy(of a person) possessing physical strength and weight; rugged and powerful“a hefty athlete”, “a muscular boxer”, “powerful arms”