Fig. 1.

Summary of the primary effects of heart failure on skeletal muscle fiber atrophy, satellite cells, and contractile dysfunction, as well as the secondary impact following prolonged exercise training in patients and animal models. ^† means in animal models only; ^‡ means in healthy individuals. ↑ means increase; ↓ means decrease; = means no change; ? means lacking information yet. HF = heart failure; ROS = reactive oxygen species; RT = resistance training; RYR1 = ryanodine receptor 1; SC = satellite cell; UPS = ubiquitin proteasome system.