If you’ve been diagnosed with cancer, get ready for a new Rx … it may surprise you: exercise.

Building on data from around the world, the Clinical Oncology Society of Australia brought together 20 health organizations to create a position statement saying: “Exercise (is) to be embedded as part of standard practice in cancer care and to be viewed as an adjunct therapy that helps counteract the adverse effects of cancer and its treatment.” Furthermore, withdrawing from exercise after diagnosis or while undergoing treatment actively harms cancer patients’ chances of survival.

As the chair of the society’s Exercise and Cancer Care Group, professor Prue Cormie, put it: “If we could turn the benefits of exercise into a pill it would be demanded by patients, prescribed by every cancer specialist and subsidized by government — it would be seen as a major breakthrough in cancer treatment.”

How does it help?

>> Fights fat: We know cancer cells love fat for fuel, and they thrive in an inflammatory environment created by excess visceral fat. Furthermore, overweight and obesity are linked to the development of many cancers. In 2012 in the United States, about 28,000 new cases of cancer in men (3.5 percent) and 72,000 in women (9.5 percent) were due to being overweight or obese. And if it can help trigger a cancer, it also may sustain it. Exercise (along with a healthy diet) reduces body fat.

>> Strengthens the heart: Chemotherapy and radiation can be hard on the cardiovascular system. Appropriate exercise may help overcome side effects.

>> Helps dispel stress: Diagnosis and treatment of cancer create a lot of personal and caregiver stress, and chronic elevation of stress hormones causes bodywide inflammation. The National Cancer Institute says, “Evidence from experimental studies does suggest that psychological stress can affect a tumor’s ability to grow and spread.”

Exercise is a very effective way to get rid of built-up stress hormones and bodywide tension. It also reduces inflammation and helps create an environment that fights off cancer instead of nurturing it. Do it with a buddy/caregiver to help you both, and you’ll improve your quality of life.

>> Reduces fatigue: Fatigue, as a side effect of treatment, is very common. The National Comprehensive Cancer Network, a not-for-profit alliance of 27 cancer centers states that “research has … demonstrated that those who exercised regularly had 40 to 50 percent less fatigue, the primary complaint during treatment.”

>> Protects bone and muscle strength: Chemo and some radiation can erode bone density. Making sure to get regular physical activity (including weight-bearing, if doc says OK) and eating a balanced diet with plenty of calcium (dark leafy greens, low-fat dairy) are essential for bone health.

What to do?

>> Get expert guidance: You want to work with your oncologist, an exercise physiologist or physiotherapist to determine what you can safely do and to help you transition to exercising independently.

>> Start slowly, and progress over days and weeks: A five-minute walk is far, far better than no walk at all. Next week it might last eight minutes or cover more ground. Or try seated exercises for the upper body and legs.

>> Keep a daily journal to track your progress: It helps keep you motivated.

>> Your goal: The society recommends you aim for at least 150 minutes of moderate-intensity exercise (or 75 minutes of vigorous intensity) weekly, along with two to three sessions of resistance exercise, using stretchy bands or even your own body weight. From there, as you put treatment behind you, you may increase your activities.

Mehmet Oz, M.D., is host of “The Dr. Oz Show,” and Mike Roizen, M.D., is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. Email questions to youdocsdaily@sharecare.com.