What can slow breast cancer cell growth? 30-minute workout, say scientists

Just one bout of high-intensity or resistance training can cut breast cancer cell growth by up to 30 per cent by boosting anti-cancer proteins, say researchers

Even a single 30-minute session of vigorous exercise may help the body fight cancer at a cellular level, according to a new study.

 

Researchers from Edith Cowan University, Australia, have found that resistance training and high-intensity interval training (HIIT) trigger the release of muscle proteins called myokines, which can slow the growth of breast cancer cells by up to 30 per cent in laboratory settings.

 

The study, titled A single bout of resistance or high-intensity interval training increases anti-cancer myokines and suppresses cancer cell growth in vitro in survivors of breast cancer, was published in Breast Cancer Research and Treatment. It examined 32 breast cancer survivors who performed a single session of either resistance training (RT) or high-intensity interval training (HIIT).

 

What did the study find?

Blood samples taken before, immediately after, and 30 minutes post-exercise revealed a surge in anti-cancer myokines such as interleukin-6 (IL-6), decorin, SPARC, and oncostatin M.

 

When scientists exposed breast cancer cells (MDA-MB-231, a particularly aggressive type) to this exercise-conditioned blood, cancer cell growth was slashed by 19–29 per cent. HIIT, in particular, triggered a greater increase in IL-6 levels and had a slightly stronger inhibitory effect on cancer cells immediately after exercise.

How can exercise slow cancer cell growth?

According to medical scientists, muscles are not just for strength — they also act like mini “medicine factories.” During workouts, they release signalling proteins called myokines, which can: 

• Interfere with cancer cell survival and spread 
• Promote cancer cell death (apoptosis) 
• Reduce inflammation, which is linked to cancer progression 
• Improve body composition by reducing fat and increasing lean muscle mass

HIIT or resistance training: Which is better?

The study found both types of exercise effective. Resistance training (such as lifting weights) and HIIT (short bursts of intense cardio with rest intervals) each boosted myokine levels and reduced breast cancer cell growth.

 

However, HIIT produced a slightly stronger immediate effect. Researchers believe this may be due to the higher metabolic demand of HIIT, which results in a larger release of IL-6 — a myokine with anti-cancer properties.

 

The study emphasised that the best exercise is the one you can sustain consistently. Over time, both RT and HIIT improve overall fitness, reduce fat, and help regulate inflammation.

How much exercise is enough to help?

While the study showed that even one session had measurable effects, it underscored the importance of long-term exercise habits. Regular physical activity ensures repeated bursts of protective myokines, alongside long-term benefits such as improved strength, reduced inflammation, and better immunity.

 

Importantly, the researchers noted that losing weight alone without exercise does not offer the same protection. It is the muscle-building activity that releases cancer-fighting myokines.

What does this mean for breast cancer survivors—and everyone else?

For survivors: Exercise is not just safe, it is potentially therapeutic. Adding resistance training or HIIT to weekly routines could provide an added layer of protection by increasing muscle mass, reducing fat, and lowering systemic inflammation.

 

For everyone: Although this study focused on breast cancer survivors, the broader idea that exercise-induced myokines help suppress cancer cells has been seen in other cancers as well. This reinforces the view that regular workouts may not only protect the heart and waistline, but also contribute to cancer defence. 

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This content is for informational purposes only and is not a substitute for professional medical advice.