People with cancer who take part in exercise can improve their quality of life, concludes two new reviews of evidence published by The Cochrane Collaboration.
US researchers gathered evidence from around the world involving almost 100 trials that showed activities such as walking and cycling could benefit people who were either undergoing or had completed treatment for cancer.
However, the researchers have qualified their findings by saying that exercise is not automatically suitable for everybody and more work needs to done to identify which types of exercise are best.
For the first review, the team looked at the results of 56 trials involving 4,826 people being treated for different types of cancer.
The second review involved data from 40 trials involving a total of 3,694 people who had completed treatment for cancer.
Both studies compared the quality of life of cancer patients who exercised with that of patients whose care did not include prescribed exercise. People who were terminally ill were not included in any of the trials.
The kinds of exercise that were studied included walking, cycling, resistance training and strength training.
Analysis of the results showed that exercise improved health-related quality of life and social functioning, and feelings of fatigue.
Patients who were undergoing treatment reported benefits in their physical well being from exercise, while those people who had finished treatment saw improvements in self-esteem, emotional well-being, sleep patterns and anxiety levels.
Lead author Dr Shiraz Mishra of the University of Albuquerque, US, said: “We need to treat these findings with caution. The trials we included looked at many different kinds of exercise programmes, which varied by type of exercise, length of the programme and how hard the participants had to exercise.
“We need to understand from future trials how to maintain the positive impacts of exercise in the longer term and whether there are particular types of exercise that are suited to particular types of cancer.”
Martin Ledwick, head information nurse at Cancer Research UK, said that although exercise was possible for some people, it was not appropriate for everyone.
“The study looked at many different kinds of activity and at several types of cancer, so further studies are needed before specific advice can be made about which exercise works best and for whom it's most appropriate,” said Mr Ledwick.
“We recommend that cancer patients check with their doctors before starting any new exercise regime.”