Recently, direct evidences point to the contributing role of peripheral muscle fatigue in exercise tolerance among patients with COPD. However, the physiological mechanisms by which peripheral muscle fatigue impairs exercise tolerance are still unknown, as factors regulating peripheral muscle fatigue in COPD may be complex. One possible link between limb muscle fatigue and exercise intolerance could be enhanced afferent signals from the active limb muscles to the central command, thereby limiting central motor output and eventually leading to exercise termination.