Regular exercise can cut by 40 percent the risk of cancer returning, say experts. Breast cancer patients who work out have more than a 40 percent lower risk of dying while prostate cancer patients 30 percent.

Exercise acts like a -wonder `drug` for survivors of some forms of the disease, according to Macmillan -Cancer Support.

Physical activity should be - `prescribed` by doctors after it was found not only to significantly help recovery but also prevent other long-term illnesses, the express.co.uk reported quoting the British-charity Monday.

Some cancers have high cure rates but others can return years after they were first treated.

Rather than patients being told to `rest up`, doctors should encourage them to get moving as soon as they feel able, researchers believe.

A review of more than 60 studies for Macmillan found that being active did not worsen people`s fatigue but had positive effects on their mood and well-being.

Once treatment has finished, exercise can reduce the impact of side-effects, such as swelling, anxiety, depression, fatigue, impaired mobility and changes to weight.

Women with breast cancer who exercise for two-and-a-half hours a week at moderate intensity have more than a 40 percent lower risk of dying and the disease returning compared with those who do less than one hour of activity a week, researchers said.

Prostate cancer patients have a 30 percent lower risk of dying from the disease and a 57 percent lower rate of disease progression if they exercise for three hours weekly.

Oncologist Jane Maher, chief medical officer of Macmillan, said: `The advice I would have given previously to my patients would have been to take it easy.

`This has now changed significantly because of the recognition that if physical exercise were a drug, it would be hitting the headlines.`

`There really needs to be a cultural change, so that health professionals see physical activity as an integral part of cancer aftercare, not just an optional add-on,` Express quoted her as saying