Water workouts may trump land-based exercise for people with chronic lung disease and other health problems, according to a small study.

Australian researchers found that exercising in a pool boosted physical endurance and energy levels in people with chronic obstructive pulmonary disease, or COPD, and physical complaints such as obesity or back pain.

"Participants in the water-based exercise training group reported an improvement in many functional aspects of their daily life such as improved stamina and ability to complete tasks such as walking long distances when shopping," said Renae McNamara, a physical therapist at The Prince of Wales Hospital in Randwick.

"They reported less fatigue, as well as less breathlessness when completing activities of daily living such as showering and dressing," she told Reuters Health by email.

COPD includes various lung diseases that cause breathlessness, such as emphysema and chronic bronchitis. About 65 million people have moderate to severe COPD, according to the World Health Organization.

There are drugs to quell symptoms of the disease, and exercise is recognized to improve the breathing problems and fatigue associated with the condition.

But many drop out of training programs, which can be particularly strenuous for people who also have other health issues. The new study, published in the European Respiratory Journal, is the first to test the benefits of exercise in this group of patients, McNamara said.

They enrolled 53 patients in the study, assigning them randomly to workouts in a hydrotherapy pool, gym-based training or standard medical care without exercise. The exercise programs include three weekly one-hour sessions over two months and 45 patients completed the study.

Whether they worked out on land or in water, patients were able walk faster after the training than when they just got usual care. But those who exercised in the pool reported less fatigue than the gym trainers and also developed more physical endurance.

On a test wherein they had to walk as far as they could at a constant speed, patients who'd exercised in water outpaced those trained in a gym by 228 meters (748 feet). Researchers consider a difference of 203 meters important.

"We believe that water-based exercise training was more beneficial for a number of reasons," McNamara said. "The water environment is unique because of the effect of buoyancy which supports the body weight, reduces forces on joints and allows greater movement; warm water assists with pain control by increasing circulation; and the water provided resistance to all movements, unlike moving on land."

There had been some concerns that people with COPD might not tolerate the pressure from the water on the chest, which makes it harder to breathe. But the researchers saw no drop-outs due to worsening COPD in patients training in the pool - they did see some in the gym group - although they caution that most of the participants in the study did not have severe disease.

McNamara said patients "also reported a very high level of enjoyment in the group water-based exercise sessions and many said they felt less depressed and felt a great sense of achievement in being able to participate in exercise training which was previously too difficult or painful on land."

Water therapy exercises are already used to treat other problems, such as arthritis and joint pain. McNamara said people interested in joining a pool-based exercise program should contact their local hospital or health provider.

"These groups may be run in hydrotherapy pools or local swimming pools," she said. "Having a supervisor to instruct, monitor and progress their exercise program is very beneficial as is the group interaction and social support which can be gained in a group session."