Exercise after cancer: could moving more stop it coming back?

For cancer survivors, the risk of recurrence is a very real fear. But what if something as simple as exercise could reduce this risk by more than 30%? That’s exactly what an exciting new study has found.

A landmark international study has found that a structured exercise regime reduces the risk of dying by a third, can stop tumours coming back or a new cancer developing.

The study, published in The New England Journal of Medicine, followed nearly 900 people treated for colon cancer. Half were given personalised exercise support for three years, while the others received health information. After nearly eight years, those in the exercise group had a significantly lower risk of their cancer returning as well as a trend toward living longer, too.

A 28% lower risk of recurrence

The numbers are striking: 80% of people in the exercise group had no signs or symptoms of cancer five years after treatment, compared to 74% in the health information group. Researchers say this is the first large-scale trial to show a clear survival benefit from exercise in cancer patients.

Dr Eva Zopf, an exercise physiologist with a PhD in exercise oncology says, “there is strong evidence that exercise reduces cancer-related fatigue and improves quality of life … and growing evidence suggests it may even improve survival outcomes.”

What about breast cancer?

So far, the clearest evidence is in colon cancer but what does this mean for exercise guidelines for people living with – and beyond – breast cancer?

There’s a lot of promising data, but no definitive trial yet. We need larger, long-term studies to confirm the impact on recurrence and survival.

Small studies in breast cancer, including trials in Canada, Australia and Sweden, have hinted at similar benefits.

In Canada’s START trial, women with early-stage breast cancer were randomised to exercise (either aerobic or resistance) during chemotherapy. After seven years, there were signs that exercise might improve both disease-free and overall survival, but the differences weren’t statistically significant.

In Australia, the Exercise for Health trial found a more striking result: women who joined an exercise programme after surgery had a 55% lower risk of death compared to those who received usual care. But again, because survival wasn’t the trial’s main focus, researchers caution that these findings need to be confirmed in larger, more rigorous studies.

Lastly, a Swedish trial known as Opti Train took a different approach, offering women high-intensity interval training during chemotherapy, followed by long-term support. After nine years, survival rates weren’t significantly higher, but the women who did resistance-based exercise had fewer recurrences of invasive breast cancer.

Together, these studies hint at a powerful effect of exercise but not enough to change clinical practice or replace standard treatments. What they do show is that exercising after a cancer diagnosis is safe, doable, and likely beneficial.

Even without definitive survival data, the benefits of exercise after breast cancer are clear. It reduces fatigue, supports mental health, and helps people stay stronger during and after treatment. Guidelines already recommend at least 150 minutes of moderate activity per week for cancer survivors.

Regardless of definitive large-scale studies, the message is simple: keep moving.

Professor Sir Stephen Powis, the national medical director of NHS England said, “being more active can have significant benefits in helping maintain a healthy weight, strengthen the immune system, reduce inflammation and lift mood – and it’s now really encouraging to see that exercise really could have the power to help more people survive cancer.”