LONDON - Weightlifters may be at risk from a newly emerging distorted body image syndrome which could be a negative consequence of their training, scientists said on Tuesday.

Although pumping iron has given them muscular and toned bodies, men suffering from muscular dysmorphia (MD) have a poor body image. They are convinced they look scrawny and are driven to work harder to enhance their physique.

"Muscle dysmorphia is a new syndrome characterized by highly muscular individuals (usually men) having a pathological belief that they are of very small musculature," said Dr. Precilla Choi, of Victoria University in Melbourne, Australia.

In addition to thinking that their muscles are not big enough, men suffering from MD are also worried about gaining fat and are particularly concerned about the shape and look of their buttocks, hips, thighs and legs.

MD is a unique form of body dysmorphic disorder (BDD), a condition in which people are abnormally preoccupied with a real or imagined defect of their physical appearance. Someone with BDD may think their nose is too long or their legs are too fat, which may lead to depression and anxiety.

Instead of being unhappy with a particular body part, men suffering from MD are dissatisfied with their entire body.

Choi said the results of her study, which are reported in the British Journal of Sports Medicine, suggest that more research into the perception of the body and health is warranted.

"If more men are taking to the gym in order to increase their musculature, some may be at risk of developing MD," she added.

Choi and her colleagues interviewed 24 regular weight trainers who had been diagnosed with MD and 30 other men who also worked out in gyms in and around Boston, Massachusetts.

Men with MD believed they were less healthy and physically attractive than the other men and were more dissatisfied with their muscle tone, weight and overall appearance.

"How to prevent this and, if it occurs, what to do about it are important questions for both researchers and practitioners," Choi added.