Many athletes seek to lose weight or maintain a low body weight for competition. For example, wrestlers, boxers, rowers, jockeys, and other athletes often compete in events in which there are rigorous weight requirements or specified weight classes that can not be exceeded for participation. Other athletes, such as gymnasts, ballet dancers, and bodybuilders, participate in sports in which they are judged on aesthetics in movement and form. Many of these athletes are often preoccupied by their body weight, are more likely to have nutritional inadequacies, and appear to be more predisposed to disordered eating (such as anorexia nervosa and bulimia nervosa).