Exercise can lower the chance that cancer comes back. The link between exercise and cancer recurrence is no longer a hopeful guess. In 2025, a randomized trial of 889 colon cancer survivors found that people who followed a coached exercise program after chemotherapy were 28% less likely to see their cancer return, develop a new cancer, or die than people who received education materials alone.1 Eight years later, 90% of the exercise group were alive, compared with 83% of the comparison group.
Earlier this month the New York Times brought that research to its front page and asked why so few patients hear about it. I’m an exercise physiologist with an additional ACSM-ACS Cancer Exercise Specialist certificate, and helping people exercise before, during, and after cancer treatment is one of the most rewarding parts of my work at Applied Fitness Solutions. Below is what the research shows, what it doesn’t show yet, and what we see every week on our training floor.
What the Research Shows About Exercise and Cancer Recurrence
The trial, called CHALLENGE, ran at 55 cancer centers. Everyone in it had stage III or high-risk stage II colon cancer and had finished surgery and chemotherapy. Most were not exercising much when they joined.
Half received health education materials. The other half received the same materials plus three years of support from a trained exercise coach. They met every couple of weeks at first, with supervised workouts, and the support tapered over time. Participants picked activities they could stick with, and brisk walking was the go-to example. By the end, the exercise group was doing roughly an extra 1.5 to 2 hours of brisk walking a week compared with the education group.
CHALLENGE trial results
889 colon cancer survivors after surgery and chemotherapy
Alive and free of cancer at 5 years
Alive at 8 years
“Free of cancer” means no recurrence and no new cancer. Source: Courneya KS, et al., New England Journal of Medicine, 2025.
That modest change lowered the risk of recurrence, new cancer, or death by 28%. Dr. Christopher Booth of Queen’s University, one of the trial’s leaders, told the Times, in effect, that a drug with this much benefit would become standard care overnight. As a clinician, it’s incredibly exciting to think I might be able to help people in such a significant way.
If you are recovering from colon surgery right now, our founder Mike Stack covers the first weeks back in Exercising After Bowel Surgery: Protect Your Guts!
What About Breast, Prostate, and Other Cancers?
CHALLENGE is the first randomized trial to show that exercise lowers recurrence, and it studied colon cancer. For breast and prostate cancer, years of observational research point the same direction, and an international panel convened by the American College of Sports Medicine concluded in 2019 that exercise helps improve survival after both.3 Those studies show a strong pattern but can’t fully prove cause and effect, so we’ll be watching for trials in other cancers.
The benefits during and after treatment are better established. The same panel found strong evidence that about 30 minutes of aerobic exercise three times a week reduces fatigue, anxiety, and depression and improves quality of life and physical function, with twice-weekly strength training helping most of the same outcomes.3
Lab research is starting to explain why. A 2026 Yale study in mice found that working muscle pulls in glucose that tumors would otherwise use to grow, even with modest amounts of exercise.4 That finding comes from animals, but it gives the human results a plausible mechanism.
Fair Questions From Skeptics
“Aren’t healthy people just more likely to exercise?”
That was a fair criticism of the older research, which compared people who chose to exercise with people who didn’t. CHALLENGE solved that problem by randomly assigning who got the exercise program. That’s why oncologists are treating this result differently.
“Is this only true for colon cancer?”
The randomized proof so far is for colon cancer. We won’t claim more than the research shows. For other cancers the evidence is strong but observational, and the benefits for energy, mood, strength, and quality of life apply across cancer types.
“Is exercise safe during or after treatment?”
For most people, yes. The ACSM panel concluded that exercise is generally safe for cancer survivors, with medical clearance advised in some situations.3 The CHALLENGE exercise group did have more muscle strains than the comparison group, which is a good argument for starting lighter than you think and progressing with qualified help.1
Member safety is our top priority. Some safety issues are obvious, such as a port or an ostomy. The intake meeting will reveal less visible risks, such as fatigue, neuropathy, cardiorespiratory issues, and bone health considerations, so we can take all of them into account when designing the exercise program.
“If someone’s cancer comes back, did they not exercise enough?”
No. Exercise lowers risk. It does not remove it, and nobody should carry guilt for a recurrence. Cancer is complicated, and plenty of it is outside anyone’s control. Exercise is one of the few things that is in your control, and that is the reason to do it.
“Does exercise replace treatment?”
No. It works alongside the care your oncology team provides. For example, we have designed programs that line up with treatment schedules so that recovery comes first and exercise sessions take place when they can be most effective.
Evidence From Our Training Floor
Before coming to AFS I worked at the Ann Arbor YMCA for four years, and during that time I ran the Y’s “LIVESTRONG at the YMCA” exercise program for cancer survivors. I worked with dozens of people in all stages of cancer survivorship: from people recently diagnosed who wanted to be more fit before starting treatment, to people who wanted to be in structured exercise during treatment, to people who were several days to several decades post-treatment. Since joining AFS in 2022 I’ve worked with at least a dozen cancer survivors.
Cancer survivors are not a monolithic group. While it’s critical for me to understand the physiological and emotional effects of various cancers and treatments, the guiding light in helping a member gain the benefits of exercise is listening to what they are experiencing and what they are looking for. At AFS most of the cancer survivors I’ve worked with were already avid exercisers. One member who was diagnosed with breast cancer said the following:
“It was important for me to keep being consistent with the routines I had before diagnosis, surgery and treatment because it gave me a sense of normalcy. Exercise has always been a spiritual practice for me. It keeps me grounded and is an activity where I connect with and pay attention to my body. Exercising gave me a sense of control over the uncontrollable.”
AFS member, breast cancer survivor
Another member trained with us before surgery and kept coming in through radiation:
“After going through cancer surgery and 40 sessions of radiation, I cannot thank you enough for what the AFS team did for me, both mentally and physically, before surgery and during the radiation treatments! My recovery from surgery was extremely rapid and, as one of the rad techs said, ‘You have to stop doing sit-ups getting off the table!’ Thank you, guys, for everything and keeping me going. I couldn’t have done it alone!”
AFS member, after surgery and radiation
A third member started after surgery, slowly, with rehabilitation as the first goal:
“After being diagnosed with cervical cancer, I knew exercise would become a tool to help me both mentally and physically prepare for the treatments and path ahead. After undergoing tests and procedures that included major surgery, I began my exercise routine slowly and focused on rehabilitation. I believe the slow and consistent process has helped my recovery tremendously and exercise will be a permanent part of my life.”
AFS member, cervical cancer survivor
One pattern stands out in both the trial and our gym: people do better with support. The Times noted that many patients need a structured program, with a trainer and supervised sessions, to reach the recommended amount of exercise and stick with it.
In CHALLENGE, even with regular coaching, the share of people still following the program fell from 83% early on to 59% by the end of year three.2 Dr. Kathryn Schmitz, who leads exercise oncology work at UPMC Hillman Cancer Center, put it simply to the Times: “Exercise is not just biology. It is also behavior.” The coaching, the check-ins, and a community that notices when you miss a week are what keep people exercising long enough for the benefits to add up.
The AFS model is built around the idea that people benefit from support, and this support can take many forms. Sometimes it’s about consistency in showing up, or for others it might be about motivation to complete a set, to increase the load, or to try something new. The bottom line is we’re here for you!
What an Exercise Program for Cancer Patients Looks Like
The research-backed starting point is simpler than most people expect:3
- Aerobic exercise, such as walking or cycling, gradually progressing toward about 30 minutes three times a week at a pace where you can still talk.
- Strength training twice a week, gradually progressing to one exercise for each major muscle group, 2 sets of 8 to 15 reps, adding weight in small steps.
- Over time, work toward 150 minutes of moderate exercise a week, the amount current colon cancer guidelines recommend.
How you get there depends on where you are in treatment.
Before, during, and after treatment
Tap a stage to see how the goals change.
“Prehab” is exercise in the weeks before surgery or other treatment, and researchers have studied it across several cancers. The clearest evidence comes from lung cancer surgery, where a 2025 review of 11 trials found that people who exercised beforehand had about half as many complications and left the hospital about two and a half days sooner.5 Results for abdominal, gastrointestinal, and prostate surgeries are more mixed so far. Even so, building strength and aerobic fitness before treatment is low risk, and it raises the level of fitness you start your recovery from.
Treatment changes from week to week, so the plan changes with it. On an infusion day, and often for a day or two after, a short walk or a few minutes of gentle mobility work may be all your body wants, and that still counts. On better days we bring strength training back in at lighter loads. Some days rest is the right call. A fever, unusual shortness of breath, dizziness, or a low blood count are reasons to skip the session and check in with your oncology team.
Once treatment ends, most people want their old strength and energy back right away. Fatigue can linger well after the last appointment, so we rebuild in steps: walking time first, then strength training with small jumps in weight, working toward the 150 minutes a week that colon cancer guidelines recommend. The CHALLENGE program supported people for three years rather than a few weeks, and its survival results were measured over eight. We plan with that same long view from your first session after treatment.
Exercise and Cancer in Ann Arbor: How We Help
At Applied Fitness Solutions, cancer exercise starts with an assessment with a qualified exercise physiologist. Our exercise physiologists hold master’s degrees in exercise physiology, and I hold the ACSM-ACS Cancer Exercise Specialist certificate. Your baseline assessment measures where you are today: your strength, how you move, your treatment history, and what your oncology team has asked you to watch for.
From there, our exercise physiologists write a program that fits your goals and your treatment schedule, and adjust it as you go, in person in Ann Arbor or remotely.
Exercise and Cancer FAQs
Can exercise prevent cancer from coming back?
For colon cancer, a large randomized trial found a structured exercise program lowered the risk of recurrence, new cancer, or death by 28%.1 For other cancers the evidence is observational but points the same way. Exercise lowers risk; it does not guarantee anything.
Is it safe to exercise during chemotherapy?
Yes. If you are cleared by your physician, research shows that it’s not only safe, but can help reduce fatigue, help with sleep, and improve your mood, among other health benefits. It’s important to start slowly, progress gradually, and listen to your body, especially right after an infusion. Rest and recovery are important parts of your treatment too.
Does exercise make cancer spread faster?
No. There is no evidence in people that exercise makes cancer spread faster. In the CHALLENGE trial, the exercise group had fewer recurrences and new cancers than the comparison group, and the ACSM panel concluded that exercise is generally safe for survivors.1,3 Most research on exercise and the spread of cancer comes from animal studies, and those point to regular moderate exercise as the most protective.6
What is the best exercise for cancer patients?
The one you’ll keep doing. The best-supported combination is moderate aerobic exercise plus twice-weekly strength training, scaled to where you are in treatment.
How much exercise do cancer survivors need?
Start with about 30 minutes of aerobic exercise three times a week plus two strength sessions, and build toward 150 minutes a week over time.
Cancer takes a lot of control out of your hands. Exercise gives some of it back, and now we have proof that it can change outcomes, too. You don’t have to start big, and you don’t have to figure it out alone.
Want a Plan That Fits Your Treatment?
Start with a free consultation. We’ll talk through where you are in treatment and what your oncology team has asked you to watch for, then set up your baseline assessment with an exercise physiologist.
Book a Free ConsultationDisclaimer: This article is general education, not medical advice. Talk with your oncology team before starting a new exercise program.
Sources
- Courneya KS, et al. Structured exercise after adjuvant chemotherapy for colon cancer. New England Journal of Medicine, 2025.
- Liu FF, Khan KM, Yeung RSM. Time to fund exercise programmes for cancer survivors: the evidence is mounting. British Journal of Sports Medicine, 2026.
- Campbell KL, et al. Exercise guidelines for cancer survivors: consensus statement from international multidisciplinary roundtable. Medicine & Science in Sports & Exercise, 2019. Summaries: National Cancer Institute and ACSM infographic.
- Yale School of Medicine. How exercise slows tumor growth. January 2026 (study published in PNAS).
- Steffens D, Hancock M, Jiang W, et al. An updated systematic review and meta-analysis of unimodal prehabilitation with exercise intervention to enhance postoperative outcomes in cancer surgery. Anesthesia & Analgesia, 2025.
- van Doorslaer de ten Ryen S, Deldicque L. The regulation of the metastatic cascade by physical activity: a narrative review. Cancers, 2020.