FRIDAY, Feb. 22 (HealthDay News) -- Regular exercise in a heated swimming pool can benefit people with the common, painful condition fibromyalgia, a new study suggests.

Symptoms of fibromyalgia include chronic and severe pain and tenderness in muscles, ligaments and tendons; neck and shoulder pain; sleep problems; anxiety and depression. Women account for more than 90 percent of people with fibromyalgia, which has no known cause or cure.

Current treatments include painkillers, exercise, relaxation therapy, and low-dose antidepressants, according to background information in a news release about the study, which was published Feb. 21 in the journal Arthritis Research & Therapy.

The study from the University of Extremadura in Spain and the University of Evora, Portugal, included 33 women with fibromyalgia -- 17 did supervised one-hour exercise sessions in a heated pool three times a week for eight months, while the other 16 did no aquatic training.

The researchers found that the long-term aquatic exercise helped reduce fibromyalgia symptoms and improved the women's health-related quality of life. In an earlier study, the same researchers found that a short-term exercise program helped ease symptoms, but pain returned when patients completed the exercise regimen.

"The addition of an aquatic exercise program to the usual care for fibromyalgia in women is cost-effective in terms of both health care costs and societal costs," and "appropriate aquatic exercise is a good health investment," the researchers wrote.

They have yet to compare aquatic training with other forms of gentle exercise such as walking, tai-chi and low-impact aerobics.

More information

The American College of Rheumatology has more about fibromyalgia.