Strengthening muscle.
D006801:Humans; D007537:Isometric Contraction; D007596:Joints / Q000033:anatomy & histology; D009119:Muscle Contraction; D009132:Muscles / Q000033:anatomy & histology / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D005082:Physical Exertion; D012146:Rest; D013997:Time Factors