(British Medical Journal) -- Prescribed graded aerobic exercise is a simple, cheap, and effective treatment for people with fibromyalgia (medically unexplained chronic muscular pain and joint tenderness), finds a study in this week's BMJ.

Researchers identified 132 patients with fibromyalgia who were attending a hospital rheumatology clinic between January 1997 and June 1998. Patients were then randomly assigned to either aerobic exercise classes or relaxation classes, twice weekly for 12 weeks. The classes were carried out by personal trainers with no special experience in providing exercise for people with ill health.

Compared to relaxation, exercise led to significantly more participants rating themselves as much or very much better at three months. Benefits were also maintained or improved one year later.

These results show that a three month programme of prescribed graded aerobic exercise is an effective treatment that leads to improvements in self reported health status, say the authors. Furthermore, prescribed exercise can be undertaken effectively in the community by personal trainers previously inexperienced in managing people with ill health.

However, compliance with exercise treatment is a considerable problem, giving high drop out rates, say the authors. Future strategies to increase the efficacy of exercise as an intervention should confront this issue, they conclude.