sport and cancer

Sport and cancer is not always an obvious combination. Yet regularly putting on your shorts to do a sports activity reduces the risk of breast cancer.

With close to one woman in nine across the world affected by this disease during the course of their lives, breast screening is vital. Among other preventative measures, physical exercise has quite a few solid arguments.

Here is the state of play with regards to breast cancer prevention with sport.

Physical activity and risk of breast cancer

The assessment is clear: close to a third of breast cancer cases are linked to a sedentary lifestyle. Numerous scientific studies demonstrate the role played by sport in combating the disease preventatively, by seizing the opportunity to get active on a daily basis, as a means of preserving your health.

In 2006, the Cancer Epidemiology, Biomarkers and Prevention journal highlighted, in a study ordered by the MGEN covering over 100 000 French women, the link between physical activity and the risk of getting breast cancer.

Women having declared doing a physical and sports activity over 5 hours or more per week saw their chances of getting breast cancer drop by 38 % compared to women who didn't do any sport – whatever the preexisting risk factors (family history, excess weight, first child after 30 years of age, etc.). It's important to specify that this data corresponds to sustained sports activities such as fitness walking, judo, dancing, swimming, squash amongst other sports.

Nevertheless, for Marie-Françoise Legillon of the DECATHLON Health Team "this is not about saying “I don't want to have breast cancer, I'm going to go running” that's not it. Common sense would be to say to yourself, I run several times a week and I put the emphasis on regularity." "

A more effective form of prevention relies on repeated and intensive effort

It would appear that the key to protecting yourself, is by doing intensive and regular sports sessions. In 2013, the American Scientific review Plos One published a study according to which women who walked an hour a day reduced their exposure to breast cancer by 14 %. The same study highlighted that doing a sport intensively one hour a day reduced the risk by 25 %.

Dr Thierry Bouillet, a cancer specialist, and co-founder of CAMI Sport & Cancer explains how sport acts against the development of breast cancer.

"Firstly, given glucose consumption, physical activity lowers insulin levels, a factor in the growth of cancerous cells.

Secondly, it lowers the quantity of oestrogen, which is also a growth factor in tumorous development, whether before or after the menopause.

Lastly, it reduces the presence of cytokines, proteins coming from abdominal fat which is at the root of malignant cells.

Physical activity, done at a certain intensity, therefore burns off three toxic factors that otherwise fuel breast cancer growth and subsequently possesses an obvious organic preventative effect. "

physical fitness - sport and cancer

From a medical perspective, this results in a lower risk in the region of between 20 to 25 %, meaning less than a quarter of the risk of cancer so long as you do at least three sessions per week of between 20 minutes to 1 hour.

Why three sessions?

"Each time you do sport, you lower your level of insulin during 72 hours, which easily covers the week" explains Dr Bouillet. Just need to maintain the frequency, which is why "you mustn't forget to look at getting enjoyment out it and find yourself a suitable activity!”.


Sources :

- Tehard B, Friedenreich CM, Oppert JM, Clavel-Chapelon F. « Effect of physical activity on women at increased risk of breast cancer: results from the E3N cohort study », Cancer Epidemiology Biomarkers Prev. 2006;15(1):57-64.

- Paul T. Williams « Breast Cancer Mortality vs. Exercise and Breast Size in Runners and Walkers », Plos One, December 2013.


In general, regular physical exercise, in the context of cancer prevention, is unanimously supported among health professional.

We often observe a vicious circle among cancer patients during a course of care where there will be a loss of cardiorespiratory capacity and muscle strength due to the different treatments. This is, in turn, leads to a reduction in physical exercise, an increase in sedentary lifestyle… All this being increased by anxiety, loss of self-confidence, changes to the body, secondary effects of treatment, fatigue…

Finding a way of taking up a sport again, through a suitable physical activity, can prove to be especially beneficial: increasing cardiorespiratory capacity, improving muscle mass and strength, benefiting body shape (obesity is part of the risk factors but is also highly linked to the risk of relapse).

sport and cancer


- Breast cancer is the leading cause of death among women.~In 50% of cases, we find identifiable risk factors, lifestyle factors (smoking, excess weight and inactivity, poor diet… and physical activity).

- The benefits of physical activity are valid when faced with any type of cancer, even if these benefits are more striking for cancers linked to hormones.

- Even after diagnosis, a suitable physical activity has a beneficial effect.

- Should sport be included as part of a care programme?~Yes because we also observe other benefits: physical fitness, quality of life, anxiety, tiredness levels, diet, improved bone density...but also self-esteem.

- And physical activity after cancer?~Physical activity has a long-term effect by improving physical and mental health, as well as quality of life in general. Without neglecting its role in preventing the risks of a relapse.


So don't hold back, jump into your running shoes, hop on to your bike or grab your racket….

By doing a physical activity, you'll not only be getting plenty of enjoyment out of a sport, but on top of that, you'll be taking care of your quality of life, stacking all the odds in your favour in preserving your health!


Obviously, nothing will replace your doctor's advice. When taking up a sports activity again, activities as part of a course of care, increasing intensity of physical effort... the advice of your doctor, or a health professional's remains vitally important.