Why exercise should be part of standard cancer treatment

When I first began researching the effects of exercise during chemotherapy in the Netherlands in 2009, the reactions from clinicians were almost always the same: “Do you realise how sick people are? We can’t ask them to exercise!”

The science has shifted dramatically since then. We now have a body of evidence, large trials, long‑term follow‑ups, and real‑world clinical experience, showing that physical activity during and after cancer treatment has an extraordinary therapeutic benefit.

It can improve chemotherapy completion rates. It reduces nausea, fatigue, constipation, diarrhoea, and other debilitating side effects of chemo. It helps people maintain muscle mass and physical function. Crucially, we’re now seeing good evidence that it can improve survival rates.

If exercise was a pill, clinicians would prescribe it. I saw the shift in clinical culture around cancer and exercise in the Netherlands a decade ago. When patients who exercised turned up for their appointments, fitter, coping with their treatment better and recovering from it more quickly, clinicians stopped asking whether exercise was possible, and started asking how to make it standard practice. Talking about physical activity became embedded in routine cancer care, along with talking about chemotherapy schedules or surgical options.

Here in New Zealand, we have some way to go. Quite rightly, we still focus on removing or shrinking the tumour and getting rid of any stray cancer cells. But cancer treatment can take over a person’s life. It’s analogous to a runaway train: you get on, you endure it, and then suddenly it’s over. Patients often describe feeling as if they’ve been left stranded on the platform. Friends congratulate you, but you’re thinking: now what? Will the cancer come back? What can I do to stop it from doing so?

Exercise is not a cure, but it’s something most people can do during their treatment to help their recovery, and reduce the chance of cancer recurring once they’ve finished treatment.

In early 2025, oncologists from all over the world were stunned by the results of the Canadian “Challenge” trial, which showed that supervised exercise could reduce the risk of colon cancer recurring in patients who had surgery and chemotherapy by nearly 30 percent.

The study, published in the New England Journal of Medicine, captured the attention of clinicians globally, but the finding – that physical activity during and after chemotherapy improves survival rates – wasn’t news to me or my colleagues.

As I described above, exercise has become a part of the standard cancer treatment plan in the Netherlands; patients expect it, clinicians prescribe it, physiotherapists support it.

I often say that New Zealand is 12 hours ahead of Europe, but 12 years behind on exercise oncology. Patients might be advised or encouraged to keep active, but exercise is not an integrated part of cancer treatment.

It should be. Exercise is one of the few parts of cancer care where patients can feel ownership, something they can choose to do, today or tomorrow, ideally with support tailored to them.

The Challenge trial was an extraordinarily well-resourced study that involved 889 patients across 55 sites (mostly in Canada and Australia) who had stage III or high-risk stage II colon cancer.

Half were randomly assigned to the exercise group (which provided supervised support for physical activity over three years), the other half to the health-education group, who were given health-education materials (hand-outs) about what and how much exercise they should do.

Eight-year survival was 90.3 percent in the exercise group, compared with 83.2 percent in the education group. This was good news for both groups, but startlingly good for those in the exercise group.

The study made the curative benefits of exercise “real” to many in the cancer field.

The exercise prescribed and supervised in the study wasn’t extreme. It was the equivalent of brisk walking for 45-60 minutes three or four times a week or jogging for 25-30 minutes. Swimming, yoga, and resistance training also counted.

But the trial also showed that supervision was critical. Participants were supported every two weeks in the first year, then monthly in the second. Without that support, the participants didn’t do the recommended amount of exercise, and the benefits dropped off.

New Zealand has extraordinary cancer specialists, and does world-class research, yet we lag behind comparable countries in integrating exercise into cancer pathways and treatment. Unlike cardiac rehabilitation, where exercise is a core part of care, exercise oncology isn’t consistently funded, taught, or embedded in clinical systems.

This means only those who can afford private programmes can access specialised guidance. That’s inequitable. Exercise support should not be a luxury, but a standard part of cancer care for everyone.

My colleagues and I aim to help make exercise support part of standard cancer treatment, as it is in the Netherlands and other European countries.

We are developing co-designed prehabilitation programmes starting in Auckland and Waikato, with plans to reach the whole motu.

The goal is to ensure that no matter where you live, exercise is part of the treatment plan. Exercise isn’t just a lifestyle recommendation, but a therapeutic intervention. The question now is not whether exercise belongs in cancer care, but why we are still treating it as if it doesn’t.

In the meantime, what should and could you do? When people ask me for recommendations on what exercise they should do, I say: “Do the type of exercise you enjoy doing, and that you’ll keep doing. And anything is better than nothing.”