When it comes to living well and preventing cancer, scientists long ago established that exercise and physical activity are key. 

But some cancer survivors wonder why that’s true, or which activities are best for maximizing benefits to their health.

That’s where people like Angela Fong, Ph.D., an assistant professor of applied exercise science at the University of Michigan School of Kinesiology, can help.

Fong is the director of the Exercise and Health Behavior in Oncology Laboratory,  which helps cancer survivors live longer and better lives in part by incorporating exercise and other physical activity into their everyday routines.

Fong, a member of the University of Michigan Health Rogel Cancer Center, explains that regular exercise reduces cancer risk in several different ways. 

Perhaps most important is simply weight management.

“Excess weight is linked to 13 types of cancer, including breast, colon, rectum, uterine, and kidney cancers,” Fong said, who's a kinesiologist. 

The exact reasons aren’t fully understood, she adds, but “exercise helps regulate hormones and strengthens the immune system.”

Exercise also helps to control blood insulin levels and reduces inflammation – both good things when it comes to reducing cancer risk.

Using movement post-cancer diagnosis

Preventing cancers is key, but what happens after a cancer diagnosis? 

Can establishing or continuing an exercise program improve treatment outcomes? 

Fong says the answer to that is an emphatic yes, and for some of the same reasons. 

First, losing weight after cancer treatment can be difficult, and exercise helps in maintaining a healthy weight – which in turn reduces the risk of recurrence and secondary cancers. 

But exercise after a cancer diagnosis does much more: it improves cardiovascular health and strengthens muscles, which helps stave off osteoporosis and improves survivors’ overall wellness. 

Exercise also helps reduce fatigue and improve survivors’ ability to move without pain or restriction, Fong adds, while at the same time lowering anxiety and depression.

What exercises to choose

Having established the importance of exercise both before and after a cancer diagnosis, the big question becomes which activities are best. 

And the answer to that, Fong says, is straightforward: What’s best is whatever will keep you coming back for more.

“The best exercise is one you enjoy, and will do consistently,” Fong said. 

Experts, including Fong, recommend 150 minutes of moderate-to-vigorous activity per week, in addition to two sessions of strength training targeting major muscle groups. 

Fong says examples include brisk walking, running, swimming, dancing, bicycling or any number of other dynamic activities.

“It’s important to spread the exercise throughout the week, and include warm-up and cool-down periods,” she said. 

“But if this feels overwhelming, start small.”

That could mean aiming for a brisk, 30-minute walk once a week. 

If that’s too much at first, she says, break it down into 10-minute sessions three times a day. 

Then increase time or intensity as tolerance improves. 

The science, Fong says, shows that exercise works.

“There’s strong evidence that exercise is beneficial for people diagnosed with cancer,” Fong said. 

Considering the improvements achievable in mental and physical health, she added, “these are important benefits for cancer survivors to lead long, healthy lives.”