Scientists find that just one bout of exercise can trigger the body to suppress cancer cell growth

Resistance training, alongside other forms of regular exercise, has long been a trusted method for maintaining good health.

It can lower the risk of chronic disease, slow the aging process, and help prevent obesity. Research also shows that exercising regularly reduces the risk of dying from cancer.

Now, a new study suggests that resistance training and high-intensity interval training (HIIT) may have even more benefits.

Researchers in Australia found that even a single workout could help slow the growth of cancer cells at the cellular level.

Resistance training and HIIT put to the test

The study, published in Breast Cancer Research and Treatment, focused on 32 women who had previously been treated for breast cancer, ranging from stage one to stage three.

Most participants had stage two cancer, and the average age was 59. Their average body mass index (BMI) was 28, considered overweight but not obese.

The participants were divided into two groups. One group performed resistance training, which included weight-based moves such as chest presses, seated rows, leg presses, shoulder presses, lateral pulldowns, curls, extensions, and lunges.

Each exercise was performed in sets of five, with eight repetitions per set, followed by a one- to two-minute rest.

The second group completed HIIT routines. They exercised on treadmills, bikes, rowers, or cross-trainers in seven 30-second bursts of high intensity, with three-minute rest breaks in between. Both groups exercised for about 45 minutes in total.

Blood tests were taken before the workouts, immediately after, and again 30 minutes later.

How exercise slows cancer cells

The results were striking. Just one session of resistance training or HIIT boosted levels of myokines—proteins released by muscles during exercise—by up to 47 percent.

These proteins are known to help muscles “talk” to the rest of the body, regulate metabolism, and reduce inflammation.

Inflammation is a major factor in the development of cancer cells. By lowering inflammation and supporting immune function, myokines appear to create an internal environment that slows the growth of cancer.

Researchers estimated that the increased myokine levels could slow cancer cell growth by 20-30%.

One of the biggest increases was observed in IL-6, a myokine that rose 47 percent after HIIT.

Meanwhile, the resistance training group showed a 23 percent increase in decorin, which helps regulate tissue growth, along with a 9 percent increase in IL-6.

As expected, the elevated protein levels began to decrease after exercise but remained higher than before the workout.

Lead researcher Francesco Bettariga, a PhD student at Edith Cowan University, explained the larger meaning of these findings: “By demonstrating anti-cancer effects at the cellular level, our results provide a potential explanation for why exercise reduces the risk of cancer progression, recurrence, and mortality.”

Why resistance training and HIIT were chosen

Bettariga and his team deliberately selected two distinct exercise types for comparison.

He explained: “We selected two distinct exercise modalities—resistance and aerobic training—because they provide different physiological benefits: resistance training improves muscle strength, while aerobic training enhances cardio-respiratory fitness in order to determine which exercise could drive greater cancer-suppressive effects.”

Interestingly, the study found that both workouts triggered similar anti-cancer effects.

This led researchers to believe that exercise intensity, not necessarily the type, was the key factor.

As Bettariga noted, “What stood out was that both modalities had comparable effects, suggesting that exercise intensity is the main driver of these anti-cancer changes, rather than the specific type of exercise performed.”

What this means for cancer patients

Breast cancer remains the most common cancer among women and a leading cause of death.

In the United States alone, 311,000 women are diagnosed each year, and about 42,000 die from the disease.

While the five-year survival rate is relatively high at 92 percent, that number falls to 33 percent if cancer cells spread to other parts of the body.

Even more concerning, rates are rising among younger women. Studies suggest an annual increase of nearly 1 percent between 2000 and 2019.

Experts point to hormone-disrupting chemicals and early menstruation, which extend a woman’s lifetime exposure to estrogen. This hormone can fuel breast cancer growth.

These new findings suggest that resistance training and HIIT may offer survivors an accessible and powerful tool to support recovery and prevent cancer cells from returning.

For many, knowing that just one session of exercise can help fight cancer is a message of hope.

Next steps for research

While the results are promising, the researchers acknowledged the study’s limits. The sample size was small, and it only focused on breast cancer survivors.

They plan to expand their research to test resistance training and HIIT across other forms of cancer and larger, more diverse groups.

Bettariga shared that the team also intends to study the effects of long-term exercise programs and explore how the immune system may contribute to fighting cancer cells.

The bigger picture

This study contributes to the growing body of evidence that exercise is more than a lifestyle choice—it is a form of medicine.

Resistance training and HIIT not only improve strength and endurance but may also help the body resist the spread of cancer cells.

For cancer survivors, the message is powerful: one workout could make a measurable difference inside the body.

Watch Dr. Rhonda Patrick share how exercise not only kills cancer cells but also boosts mental health:

Disclaimer: This article is for informational purposes only and is not intended to serve as a substitute for professional advice, diagnosis, or treatment. Always seek the guidance of a qualified expert or licensed professional with any questions or concerns you may have.