Research in the prevention of muscle loss and function with agehas focused on resistance training as an exercise intervention.Considerably less attention has been paid to aerobic/endurance exercise and the potential benefits of lifelongaerobic exercise. We focus this review on new evidence thatsupports the benefits of aerobic exercise on muscle mass andfunction. Recent data support that aerobic exercise, especiallylong-term, preserves the neuromuscular junction and motorunit, mitochondrial function, and proteostasis. Although morestudies are needed on exact mechanisms, it is our contentionthat aerobic exercise, like resistance exercise, can help preventthe decline in muscle mass and function with age.