Exercise is already recommended to help people with cancer manage fatigue and improve quality of life.Now, there’s evidence the benefits may go further.A new study finds structured exercise may help people with cancer live longer and have more time free of disease.Researchers analyzed 21 clinical trials involving more than 8,400 cancer patients.Some followed supervised exercise programs that included aerobic exercise, strength training or both. Others did not.Over an average follow-up of about five years, those who exercised were 23 percent less likely to die, and 17% less likely to have their cancer return before death.The benefits were strongest among people with early-stage cancer, those who did aerobic exercise — alone or with strength training — and those who completed at least 70% of their exercise program.Researchers say exercise may help the immune system fight cancer. It may also improve blood flow within tumors, helping cancer treatments work more effectively.There are some limitations. Most of the evidence came from breast cancer trials, and the programs varied widely. So, more research is needed to determine the ideal exercise prescription.Still the authors say, “Clinicians can reasonably recommend structured exercise as part of oncological care.”Source: British Journal of Sports MedicineAuthor Affiliations: National Taiwan University, National Yang Ming Chiao Tung University, Chung Shan Medical University .Sign up for our weekly HealthDay newsletter