The myth of the "exercise addicted" woman is exposed today by researchers who say those who work out in the gym for as much as two hours a day show no sign of being psychologically unhealthy.

Speculation has grown in recent years that the increase in interest in fitness, with a widespread desire among women to control their weight, is contributing to exercise addiction.

Anecdotal reports of women who have developed a damaging obsession with exercise that interferes with their work and relationships, and causes withdrawal symptoms when they stop, have raised concern. Studies of male and female runners have suggested more than one-fifth may be highly addicted and up to three-quarters moderately addicted.

Diane Bamber and colleagues at the School of Sport and Exercise Sciences at the University of Birmingham set out to test the claims in a study of 56 women who were members of sports clubs.

They found those who exercised "excessively" - an average of almost two hours a day every day of the year - showed no signs of being psychologically unhealthy, and enjoyed high self-esteem. The only difference between them and a "normal" group of women was that the former had more menstrual abnormalities.

However, a second group of women whose heavy exercise routine was linked with an eating disorder were more likely to have psychological problems, lower self-esteem and a tendency to addictive behaviour.

The authors, who publish their findings in the British Journal of Sports Medicine, conclude that a preoccupation with body image common to women with eating disorders is most likely to trigger an unhealthy obsession with exercise.

"Exercise dependence is a rare phenomenon and certainly not one with the prevalence rates reported in some previous studies," they say.

Massage used by athletes after sporting performance is useless as an aid to recovery. A study of eight amateur boxers found that muscle recovery in those given a 20-minute massage between two bouts was no different from those who had a 20-minute rest. The researchers, from University College, Northampton, do concede, however, that massage could give some psychological benefit.