Is 150 minutes of weekly exercise enough to lower your cancer risk?

When it comes to cancer, we’re always looking for hope. The details may vary in each individual case, but the dread and worry remain the same: What helps, what will save them, what can’t. And the fear intensifies on hearing words such as stages and ‘terminal’.

But hope comes in the form of research and studies, that are determined to find ways to increase your longevity, somehow. Recently, the final results from the phase 3 Colon Health and Lifelong Exercise Change (CHALLENGE) trial were published recently in the New England Journal of Medicine (NEJM), which highlighted the role of exercise in cancer prevention and treatment. Patients with cancer who took part in a structured exercise program as part of a randomised controlled trial experienced longer cancer-free survival and a reduced risk of death during the study period compared to those in the control group.

Dr. Annu Susan George, Consultant in Medical Oncology at Medcare Royal,  explains, “As early as 2006, observational studies were pointing to a link between physical activity after a colon cancer diagnosis and a reduced risk of recurrence or death. But because they were observational, they couldn’t prove causation. That’s why this trial is so important—it’s the first of its kind to offer randomised controlled trial evidence.”

In the trial, patients who had undergone complete resection of stage III or high-risk stage II colon cancer were randomly assigned to one of two groups:

The results:

Moreover, the results were not linked to weight loss, indicating that the benefit comes from movement itself, not just body weight changes.

“This trial proves that exercise is not just good for well-being, but also has measurable survival benefits in colon cancer,” Dr. George adds. “However, it’s important to understand that exercise is not a substitute for surgery or chemotherapy. All patients in the trial had completed their cancer treatment before starting the program. Exercise is an additional tool, not a replacement.”

As Soha Abdelbaky, an oncologist based at Medcare Sharjah and Ruhil Badiani, a physician at Cornerstone Clinic, Dubai told Gulf News, cancer, which is a notoriously complex disease, is likely a combination of factors. And, diets high in processed foods and a lack of physical activity are among the common reasons.

And so, a growing body of research shows the power of movement in cancer care, as Dr George explains. For instance, a meta-analysis spanning breast, lung, prostate, and colorectal cancers showed that post-diagnosis activity reduced cancer-specific death by 24–31 per cent. She also explains that multiple studies have showed that high muscle strength and cardiovascular fitness were associated with up to 46% lower risk of death in advanced cancers. “For breast cancer in particular, resistance training plays a significant role, by reducing inflammation, improving body composition, and supporting immune health.”

Even a little movement goes a long way. As Dr. George explains, just 75 minutes of activity a week, that’s about 11 minutes a day, can lower your overall cancer risk by 7 per cent. But for the best protection, aim for 150 to 300 minutes each week.

How exactly does exercise help in the fight against cancer? Scientific research shows that physical activity influences both metabolic and immune systems in ways that can reduce cancer risk, slow its progression, and even improve treatment outcomes. Here's a breakdown of the key mechanisms, as Dr George explains.

The immune surveillance

Exercise boosts the immune system’s ability to detect and destroy abnormal or potentially cancerous cells. It increases the activity and efficiency of immune cells like natural killer cells and T-cells, which play a critical role in targeting and eliminating threats before they take hold.

Reduced inflammation

Chronic inflammation is a major contributor to the development and progression of many cancers. Regular physical activity helps regulate the body’s inflammatory response, lowering levels of pro-inflammatory markers while increasing anti-inflammatory signals. This creates a less favorable environment for cancer to grow.

Improved insulin sensitivity

Cancer cells often flourish in insulin-rich environments. Exercise helps the body use insulin more effectively, reducing the amount needed to manage blood sugar levels. This leads to lower levels of insulin and insulin-like growth factors (IGFs), both of which are associated with increased cancer cell growth and metastasis, particularly in breast and colon cancers.

Exercise improves blood circulation and oxygen delivery throughout the body, including to tumor sites. This change can slow tumor progression and make cancer cells more responsive to treatment by altering the surrounding environment where tumors exist.

Hormonal regulation

Some cancers, such as breast and prostate cancer, are hormone-sensitive. Physical activity helps regulate hormone levels like estrogen and testosterone, reducing the hormonal imbalances that may fuel certain types of tumors.

How much is enough?

The US Centers for Disease Control and Prevention (CDC) had recommended that adults get at least 150 minutes of moderate to high-intensity exercise per week. If you're spreading that across five days, it breaks down to just 30 minutes a day, whether it’s a brisk walk, a jog, cycling, or swimming.

The good news: These minutes don’t need to happen all at once. The benefits of physical activity are cumulative, which means every bit counts. Even if you can’t carve out a dedicated workout session, there are plenty of ways to sneak movement into your day. For instance, just taking the stairs, instead of the elevator. That might give you 10 extra minutes of activity.

Small choices like these stack up, and they matter.

As Dr George suggests:

Dr. George stresses, “There’s a dose-response relationship. The more you move, the more protection you gain, up to a point. And even after treatment, a supervised and structured program can offer enormous benefits.”

While the benefits of exercise are increasingly clear, the role of diet remains more complex. As experts note, while processed foods are linked to chronic conditions like obesity, diabetes, and heart disease, directly connecting them to cancer is challenging due to the long and multifactorial nature of how cancer develops.

Still, diet and physical activity together form the foundation of cancer prevention strategies, and now, more than ever, movement can be a powerful form of medicine.