sinewy

Adjective

• (of a person) possessing physical strength and weight; rugged and powerful
  • a hefty athlete
    
  • a muscular boxer
    
  • powerful arms
    

• consisting of tendons or resembling a tendon

• (of meat) full of sinews; especially impossible to chew

Related words

• Synonyms: 
  brawny , hefty , muscular , powerful , tendinous , fibrous , stringy , unchewable