The ancient Chinese martial art of Tai Chi can help to improve people's health, research suggests.
Tai Chi has been used in China for centuries
Doctors in the United States analysed 47 studies looking at the impact Tai Chi had on people with chronic health problems, like heart disease or MS.
They found that it could improve balance control, flexibility and even the health of their heart.
Writing in The Archives of Internal Medicine, they said it also reduced stress, falls, pain and anxiety.
Tai Chi originated in China where it has been used for hundreds of years.
It combines deep breathing with relaxation and postures that flow from one to another through slow movements.
Practitioners say it can have a positive effect on people's health, improving memory, concentration, digestion, balance and flexibility.
They say it is also helpful for people with psychological problems, such as depression, anxiety or stress.
This latest study by doctors at Tufts-New England Medical Center in Boston suggests there is medical evidence to back up those claims.
Their findings are based on a review of studies published in English and Chinese.
"Overall, these studies reported that long-term Tai Chi practice had favourable effects on the promotion of balance control, flexibility and cardiovascular fitness and reduced the risk of falls in elders," the researchers said.
They said the martial art helped to reduce "pain, stress and anxiety in healthy subjects".
But it also had benefits for people with serious conditions, such as heart disease and high blood pressure.
"Benefits were reported by the authors of these studies in cardiovascular and respiratory function in healthy subjects and in patients who had undergone coronary artery bypass surgery as well as in patients with heart failure, hypertension, acute myocardial infarction, arthritis and multiple sclerosis."
Bob Weatherall, secretary of the British Council of Chinese Martial Arts, welcomed the findings.
"The health aspects of Tai Chi are well documented," he told BBC News Online.
"It is used extensively in hospitals in China to improve the health of patients. Hospitals in England have started using it too.
"Tai Chi is all about breathing and posture. It's about getting the mind and body to work together. Some people call it moving meditation.
"Most people practice it for its health benefits and for stress relief."