Exercise after colon cancer: what the CHALLENGE trial found
It made a real difference in this trial. CHALLENGE randomly assigned 889 people who had finished treatment for colon cancer to a 3-year coached exercise programme or health-education materials. The exercise group had a 28% lower risk of the cancer returning or a new cancer, and a 37% lower risk of death, over a median of almost 8 years. It's one trial, in one cancer type, after treatment, but it's a high-quality randomised trial, and it shows how much support to keep moving can matter.
For years, studies have noticed that people who are more active after a bowel cancer diagnosis tend to do better. But those were observational studies, and active people differ from inactive people in lots of ways. The big question was whether getting people moving actually changes outcomes.
In 2025, a randomised trial gave the clearest answer yet. Here's what it found, how much weight it can carry, and what else has good evidence for life after treatment.
What the CHALLENGE trial did
CHALLENGE ran for over 15 years at 55 centres, mainly in Canada and Australia. The results were published in the New England Journal of Medicine.
- Who: 889 people who'd had surgery and chemotherapy for high-risk stage II or stage III colon cancer, joining 2 to 6 months after chemotherapy finished.
- Groups: 445 people got a 3-year structured exercise programme with regular sessions with a coach. 444 got health-education materials about physical activity and nutrition.
- The goal: roughly 150 minutes a week of moderate activity, like brisk walking, built up gradually.
- Follow-up: a median of 7.9 years.
What it found
| Outcome | Exercise programme | Health education | Result |
|---|---|---|---|
| No cancer return or new cancer at 5 years (main outcome) | 80.3% | 73.9% | 28% lower risk (HR 0.72, 0.55 to 0.94) |
| Alive at 8 years | 90.3% | 83.2% | 37% lower risk of death (HR 0.63, 0.43 to 0.94) |
| Muscle and joint problems | 18.5% | 11.5% | More common with exercise |
In everyday numbers: at 5 years, about 6 more people in every 100 were free of cancer in the exercise group. At 8 years, about 7 more in every 100 were alive.
How robust is this?
This is about as strong as lifestyle evidence gets: a large, multi-centre, randomised phase 3 trial, with long follow-up and a clear main outcome. But it's still worth being precise about what it shows:
- One trial, one cancer. It was colon cancer after treatment. We can't assume the same result for other cancers.
- The survival result was a secondary outcome. It's encouraging, but the trial was designed around cancer returning, not survival.
- Not blinded. People knew which group they were in, which is unavoidable with exercise.
- The programme included coaching, so we can't separate the effect of the exercise from the effect of having support.
- More muscle and joint problems in the exercise group, a reminder to build up gradually.
What else has good evidence after treatment
Exercise is the headline, but it works best as part of a wider set of everyday habits. These have strong support for people who've finished cancer treatment.
| Change | What the research shows | Evidence |
|---|---|---|
| Regular aerobic and strength exercise | International guidelines found that around 30 minutes of moderate activity 3 times a week, plus strength exercise twice a week, improved fatigue, anxiety, depression, physical function and quality of life in people who'd had cancer. | Strong |
| Enough protein to rebuild strength | European nutrition experts (ESPEN) recommend adequate protein during and after cancer treatment, to help maintain muscle. Including a protein food at every meal is a simple start. | Expert guidance |
| Less processed meat | Processed meat is classed as a cause of bowel cancer (Group 1) by the International Agency for Research on Cancer, and red meat as a probable cause (Group 2A). | Strong |
| A plant-rich diet and less alcohol | The World Cancer Research Fund advises people who've had cancer to follow its recommendations unless their team advises otherwise: plenty of wholegrains, vegetables, fruit and beans, and limiting fast food, sugary drinks and alcohol. | Expert guidance |
One detail in CHALLENGE stands out: people weren't just told to exercise. They had a coach, for 3 years, helping them build and keep the habit. Support was part of the intervention.
The trial used coaching. So do I.
In CHALLENGE, the exercise group had regular support from a coach to build activity gradually and keep it going. My coaching isn't the programme tested in the trial, but it's built on the same idea: support turns good intentions into lasting habits.
Start where you are
We begin with what your body can do today, even if that's a 10-minute walk, and build gradually with your team's OK.
Make it a habit, not a chore
We tie activity to your existing routine and find movement you enjoy, so it lasts beyond the first month.
Food to rebuild strength
We make sure your meals include enough protein and plenty of plants, without strict rules.
Support through the dips
Low-energy weeks and setbacks happen. We adjust the plan instead of starting over.
My take
What strikes me most about CHALLENGE is that people weren't just handed a leaflet. That was the comparison group. The group that did better had someone helping them build the habit and stick with it for 3 years.
That's the heart of what I do. Knowing that movement matters is the easy part. Building it into your life after treatment, at a pace that feels right, with someone in your corner, is where the change happens. It's how I work with my clients.
Frequently asked questions
Does exercise reduce the risk of colon cancer coming back?
In the CHALLENGE trial, people who followed a 3-year coached exercise programme after colon cancer treatment had a 28% lower risk of the cancer returning or a new cancer than those who got health-education materials. It's one trial, so more research will help confirm it.
How much exercise did people do in the CHALLENGE trial?
The programme aimed for about 150 minutes a week of moderate activity, like brisk walking, built up gradually with a coach over 3 years.
When did people start exercising in the trial?
Between 2 and 6 months after finishing chemotherapy for high-risk stage II or stage III colon cancer.
Is exercise safe after cancer treatment?
For most people, gradually building activity is safe and helpful, but in CHALLENGE the exercise group had more muscle and joint problems (18.5% vs 11.5%). Build up slowly, and check with your team first, especially after surgery or if you have other health conditions.
Sources
- Courneya KS, Vardy JL, O'Callaghan CJ, et al. Structured exercise after adjuvant chemotherapy for colon cancer. N Engl J Med 2025. Read it
- Campbell KL, Winters-Stone KM, Wiskemann J, et al. Exercise guidelines for cancer survivors: consensus statement from international multidisciplinary roundtable. Med Sci Sports Exerc 2019;51:2375-2390. Read it
- Muscaritoli M, Arends J, Bachmann P, et al. ESPEN practical guideline: clinical nutrition in cancer. Clin Nutr 2021;40:2898-2913.
- Bouvard V, Loomis D, Guyton KZ, et al. Carcinogenicity of consumption of red and processed meat. Lancet Oncol 2015;16:1599-1600.
- World Cancer Research Fund / American Institute for Cancer Research. Cancer Prevention Recommendations.
Follow @habitiahealth on Instagram for a new evidence check most days.
I'm Shivy, a certified Integrative Nutrition Health Coach (Institute for Integrative Nutrition, 2020). I have a degree in biology and a master's in environmental science, and I've lived with psoriasis since 2019. I read the research on food, sleep, stress and movement and turn it into small, realistic habits. More about me.
This article is education, not medical advice. Always follow the advice of your GP or medical team, and check with them before changing your diet or supplements.
