Disclosed herein is a composition for promoting AMPK activity, which comprises a chito-oligosaccharide as an active ingredient. The present composition affects the enzymes related to AMPK and lipid metabolism, and thus helps recovery from the condition lacking energy by various functions of controlling metabolism. Therefore, the present composition can enhance energy metabolism, thus making the composition effective for improving exercise capacity and reducing fatigue. The present composition can be used in the preparation of food or medicinal product as an endurance builder or for the prevention and improvement of fatigue.