Being active and breast cancer.

What is the link?

Two women running through park

Does exercising reduce my breast cancer risk?

Research tells us by being physically active you can reduce your risk of developing breast cancer. Across recent studies, the most active people had an average 15% lower risk of breast cancer than the least active people. Benefits don’t just come from sports and exercise, everyday activities can count too. Simply put, the more active you are, the more you will benefit. Moving regularly throughout the day is also important as long periods of sitting have been linked to an increased risk, no matter how much exercise you do. 

Tips for increasing your activity levels.

Make movement part of your daily life.

Walk, cycle, take the stairs or do some gardening.

Anything is better than nothing.

If you’re not currently active, start small and build up gradually. Try a 10-minute walk at lunchtime.

Choose activities you enjoy.

You're more likely to stick with exercise if it feels fun rather than a chore.

Guidelines for weekly physical activity from the UK Chief Medical Officer.

Key facts about exercise and breast cancer risk.

Examples of different levels of physical activity.

How does exercise reduce your breast cancer risk?

There are several ways that physical activity can reduce breast cancer risk, including:  

Healthier hormone levels

Oestrogen is a natural hormone that plays an important role in the body to help cells grow, but higher levels are linked to an increased risk of breast cancer. Physical activity can help reduce oestrogen levels in the blood and increase levels of proteins that ‘block’ oestrogen from functioning. This means less is available to promote cell growth.  

Improved blood sugar and metabolism  

Exercise helps the body respond more effectively to the hormone that controls blood sugar, known as insulin. It may also reduce the activity of insulin-like growth factor 1 (IGF-1), a substance that can encourage cells to grow and divide. Together, these changes may help create conditions that prevent cancer development.  

Reduced inflammation 

Regular physical activity helps reduce long-term (chronic) inflammation. Chronic inflammation involves the immune system staying active when it shouldn’t be, and this has been linked to several diseases, including breast cancer. Exercise encourages muscles to release natural substances that help control inflammation, and this may reduce your breast cancer risk. It can also reduce harmful abdominal fat, which is another source of inflammatory signals in the body.  

Changes to body weight 

Exercising is an effective way to lose weight, which is important after menopause as being overweight or obese is linked to an increased risk of breast cancer for both men and postmenopausal women. See our weight key fact sheet for more information.

While excess weight is not linked to a higher risk of breast cancer in premenopausal women, it can increase the risk of several other health conditions. Maintaining a healthy weight is also linked with better outcomes after a breast cancer diagnosis. 

Video cover of a man with brown hair and glasses speaking to the camera with orange captions at bottom

Ask the scientist: what's the link between exercise and breast cancer risk?

Does exercise affect breast cancer recurrence and mortality? 

Staying physically active appears to be beneficial after a breast cancer diagnosis. Research shows that people who are most active are around 30 – 40% less likely to die from breast cancer. There is also limited evidence that physical activity is linked to lower chances of breast cancer recurrence.  

Research into these areas is ongoing, but the overall message is encouraging: keeping active after a breast cancer diagnosis is likely to benefit your wellbeing. 

What types of physical activity can I do to reduce my breast cancer risk? 

There are many ways to be active and meet the weekly guidelines; it doesn’t just mean running or lifting weights. Moderate and vigorous activity count towards the recommended weekly guidelines, but studies show that light physical activity can also benefit your health.  

Examples of different levels of physical activity.

In general, you can judge the intensity of an activity by how it affects your heart rate and breathing: 

Sedentary behaviour is when you sit or lie still for a long time while you’re awake, for example while working at a desk or watching TV. Try to break up long chunks of sitting or lying still with movement of any intensity, whenever you can. Scientists don’t yet know the optimal frequency of movement breaks, but many experts recommend moving at least once every 30 minutes.

Start your prevention journey today.

Building more physical activity into your daily routine doesn't have to be hard. Here are four easy ways to get more active: 

Remember, these small steps can make a big difference. Which one will you try first?

Further reading

For more information, read our Physical Activity and Breast Cancer science review.

Last review: Sept-26 | Next review: Sept-29

    1. Moore SC, Lee I-M, Weiderpass E, et al. Association of Leisure-Time Physical Activity With Risk of 26 Types of Cancer in 1.44 Million Adults. JAMA Intern Med 2016;176:816. https://doi.org/10.1001/jamainternmed.2016.1548 

    2. Pizot C, Boniol M, Mullie P, et al. Physical activity, hormone replacement therapy and breast cancer risk: A meta-analysis of prospective studies. Eur J Cancer 2016;52:138–54. https://doi.org/10.1016/j.ejca.2015.10.063 

    3. Hardefeldt PJ, Penninkilampi R, Edirimanne S, et al. Physical Activity and Weight Loss Reduce the Risk of Breast Cancer: A Meta-analysis of 139 Prospective and Retrospective Studies. Clin Breast Cancer 2018;18:e601–12. https://doi.org/10.1016/j.clbc.2017.10.010 

    4. Chen X, Wang Q, Zhang Y, et al. Physical Activity and Risk of Breast Cancer: A Meta-Analysis of 38 Cohort Studies in 45 Study Reports. Value in Health 2019;22:104–28. https://doi.org/10.1016/j.jval.2018.06.020 

    5. McTiernan Anne, Friedenreich CM, Katzmarzyk PT, et al. Physical Activity in Cancer Prevention and Survival: A Systematic Review. Med Sci Sports Exerc 2019;51:1252–61. https://doi.org/10.1249/MSS.0000000000001937 

    6. Matthews CE, Moore SC, Arem H, et al. Amount and Intensity of Leisure-Time Physical Activity and Lower Cancer Risk. Journal of Clinical Oncology 2020;38:686–97. https://doi.org/10.1200/JCO.19.02407 

    7. Kehm RD, Genkinger JM, MacInnis RJ, et al. Recreational Physical Activity Is Associated with Reduced Breast Cancer Risk in Adult Women at High Risk for Breast Cancer: A Cohort Study of Women Selected for Familial and Genetic Risk. Cancer Res 2020;80:116–25. https://doi.org/10.1158/0008-5472.CAN-19-1847 

    8. Liu W, An J, Jiao C, et al. The Association Between Physical Activity and risk for breast cancer in US female adults: A cross-sectional study based on NHANES 2011–2020. European Journal of Surgical Oncology 2024;50:108647. https://doi.org/10.1016/j.ejso.2024.108647 

    9. Hong BS, Lee KP. A systematic review of the biological mechanisms linking physical activity and breast cancer. Phys Act Nutr 2020;24:25–31. https://doi.org/10.20463/pan.2020.0018 

    10. Michou V, Zervoudis S, Eskitzis P, et al. Exercise Interventions in Breast Cancer: Molecular Mechanisms, Physical Benefits, and Practical Recommendations. Medicina (B Aires) 2025;61:1167. https://doi.org/10.3390/medicina61071167 

    11. Hermelink R, Leitzmann MF, Markozannes G, et al. Sedentary behavior and cancer–an umbrella review and meta-analysis. Eur J Epidemiol 2022;37:447–60. https://doi.org/10.1007/s10654-022-00873-6 

    12. Kerr J, Anderson C, Lippman SM. Physical activity, sedentary behaviour, diet, and cancer: an update and emerging new evidence. Lancet Oncol 2017;18:e457–71. https://doi.org/10.1016/S1470-2045(17)30411-4 

    13. Chan DSM, Abar L, Cariolou M, et al. World Cancer Research Fund International: Continuous Update Project—systematic literature review and meta-analysis of observational cohort studies on physical activity, sedentary behavior, adiposity, and weight change and breast cancer risk. Cancer Causes & Control 2019;30:1183–200. https://doi.org/10.1007/s10552-019-01223-w 

    14. Ekelund U, Tarp J, Steene-Johannessen J, et al. Dose-response associations between accelerometry measured physical activity and sedentary time and all cause mortality: systematic review and harmonised meta-analysis. BMJ 2019:l4570. https://doi.org/10.1136/bmj.l4570 

    15. Friedenreich CM, Ryder‐Burbidge C, McNeil J. Physical activity, obesity and sedentary behavior in cancer etiology: epidemiologic evidence and biologic mechanisms. Mol Oncol 2021;15:790–800. https://doi.org/10.1002/1878-0261.12772 

    16. Department of Health and Social Care. UK Chief Medical Officers’ physical activity guidelines 2026. https://www.gov.uk/government/publications/physical-activity-guidelines-uk-chief-medical-officers-report (accessed July 30, 2026) 

    17. World Health Organization. WHO GUIDELINES ON PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR 2020. https://www.who.int/publications/i/item/9789240015128 (accessed November 6, 2025) 

    18. Key TJ, Appleby PN, Reeves GK, et al. Sex hormones and risk of breast cancer in premenopausal women: a collaborative reanalysis of individual participant data from seven prospective studies. Lancet Oncol 2013;14:1009–19. https://doi.org/10.1016/S1470-2045(13)70301-2 

    19. Ennour-Idrissi K, Maunsell E, Diorio C. Effect of physical activity on sex hormones in women: a systematic review and meta-analysis of randomized controlled trials. Breast Cancer Research 2015;17:139. https://doi.org/10.1186/s13058-015-0647-3 

    20. Kim J-W, Kim D-Y. Effects of Aerobic Exercise Training on Serum Sex Hormone Binding Globulin, Body Fat Index, and Metabolic Syndrome Factors in Obese Postmenopausal Women. Metab Syndr Relat Disord 2012;10:452–7. https://doi.org/10.1089/met.2012.0036 

    21. Swain CTV, Drummond AE, Boing L, et al. Linking Physical Activity to Breast Cancer via Sex Hormones, Part 1: The Effect of Physical Activity on Sex Steroid Hormones. Cancer Epidemiology, Biomarkers & Prevention 2022;31:16–27. https://doi.org/10.1158/1055-9965.EPI-21-0437 

    22. Neil-Sztramko SE, Boyle T, Milosevic E, et al. Does obesity modify the relationship between physical activity and breast cancer risk? Breast Cancer Res Treat 2017;166:367–81. https://doi.org/10.1007/s10549-017-4449-4 

    23. Gunter MJ, Hoover DR, Yu H, et al. Insulin, Insulin-Like Growth Factor-I, and Risk of Breast Cancer in Postmenopausal Women. JNCI Journal of the National Cancer Institute 2009;101:48–60. https://doi.org/10.1093/jnci/djn415 

    24. Key TJ, Appleby PN, Reeves GK, et al. Insulin-like growth factor 1 (IGF1), IGF binding protein 3 (IGFBP3), and breast cancer risk: pooled individual data analysis of 17 prospective studies. Lancet Oncol 2010;11:530–42. https://doi.org/10.1016/S1470-2045(10)70095-4 

    25. Thomas RJ, Kenfield SA, Jimenez A. Exercise-induced biochemical changes and their potential influence on cancer: a scientific review. Br J Sports Med 2017;51:640–4. https://doi.org/10.1136/bjsports-2016-096343 

    26. Wang D, Zuo R, Su R, et al. Association Between Leisure Time Physical Activity and Insulin Resistance: Analysis of NHANES 2007-2018. Am J Lifestyle Med 2026. https://doi.org/10.1177/15598276261445387 

    27. Kwon YR, Kim Y, Kim Y. Exercise-induced modulation of IGF-1 in healthy, obese, and cancer populations: a systematic review and meta-analysis. Ann Med 2025;57. https://doi.org/10.1080/07853890.2025.2586331 

    28. Thomas R, Kenfield SA, Yanagisawa Y, et al. Why exercise has a crucial role in cancer prevention, risk reduction and improved outcomes. Br Med Bull 2021;139:100–19. https://doi.org/10.1093/bmb/ldab019 

    29. Hojman P, Dethlefsen C, Brandt C, et al. Exercise-induced muscle-derived cytokines inhibit mammary cancer cell growth. American Journal of Physiology-Endocrinology and Metabolism 2011;301:E504–10. https://doi.org/10.1152/ajpendo.00520.2010 

    30. Ringleb M, Fabritius F, Godde J, et al. Circulating Myokine Responses to Acute Endurance Exercise and Their Role in Immunoregulation: A Systematic Review and Meta‐Analysis. The FASEB Journal 2026;40. https://doi.org/10.1096/fj.202504780R 

    31. Booth A, Magnuson A, Fouts J, et al. Adipose tissue, obesity and adipokines: role in cancer promotion. Horm Mol Biol Clin Investig 2015;21:57–74. https://doi.org/10.1515/hmbci-2014-0037 

    32. Danforth DN. The Role of Chronic Inflammation in the Development of Breast Cancer. Cancers (Basel) 2021;13:3918. https://doi.org/10.3390/cancers13153918 

    33. Pierce BL, Ballard-Barbash R, Bernstein L, et al. Elevated Biomarkers of Inflammation Are Associated With Reduced Survival Among Breast Cancer Patients. Journal of Clinical Oncology 2009;27:3437–44. https://doi.org/10.1200/JCO.2008.18.9068 

    34. Gleeson M, Bishop NC, Stensel DJ, et al. The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease. Nat Rev Immunol 2011;11:607–15. https://doi.org/10.1038/nri3041 

    35. Dehesh T, Fadaghi S, Seyedi M, et al. The relation between obesity and breast cancer risk in women by considering menstruation status and geographical variations: a systematic review and meta-analysis. BMC Womens Health 2023;23. https://doi.org/10.1186/S12905-023-02543-5 

    36. Brinton LA, Cook MB, McCormack V, et al. Anthropometric and Hormonal Risk Factors for Male Breast Cancer: Male Breast Cancer Pooling Project Results. JNCI Journal of the National Cancer Institute 2014;106. https://doi.org/10.1093/JNCI/DJT465 

    37. Luo J, Hendryx M, Manson JAE, et al. Intentional Weight Loss and Obesity-Related Cancer Risk. JNCI Cancer Spectr 2019;3. https://doi.org/10.1093/JNCICS/PKZ054 

    38. Teras LR, Patel A V., Wang M, et al. Sustained Weight Loss and Risk of Breast Cancer in Women 50 Years and Older: A Pooled Analysis of Prospective Data. JNCI Journal of the National Cancer Institute 2020;112:929. https://doi.org/10.1093/JNCI/DJZ226 

    39. García-Estévez L, Cortés J, Pérez S, et al. Obesity and Breast Cancer: A Paradoxical and Controversial Relationship Influenced by Menopausal Status. Front Oncol 2021;11 

    40. Torres-De La Roche LA, Steljes I, Janni W, et al. The Association between Obesity and Premenopausal Breast Cancer According to Intrinsic Subtypes – a Systematic Review. Geburtshilfe Frauenheilkd 2020;80:601. https://doi.org/10.1055/A-1170-5004 

    41. Renehan AG, Pegington M, Harvie MN, et al. Young adulthood body mass index, adult weight gain and breast cancer risk: the PROCAS Study (United Kingdom). Br J Cancer 2020;122:1552. https://doi.org/10.1038/S41416-020-0807-9 

    42. Cariolou M, Abar L, Aune D, et al. Postdiagnosis recreational physical activity and breast cancer prognosis: Global Cancer Update Programme ( CUP Global) systematic literature review and meta‐analysis. Int J Cancer 2023;152:600–15. https://doi.org/10.1002/ijc.34324 

    43. Delrieu L, Jacquet E, Segura-Ferlay C, et al. Analysis of the StoRM cohort reveals physical activity to be associated with survival in metastatic breast cancer. Sci Rep 2020;10:10757. https://doi.org/10.1038/s41598-020-67431-6 

    44. Spei ME, Samoli E, Bravi F, et al. Physical activity in breast cancer survivors: A systematic review and meta-analysis on overall and breast cancer survival. Breast 2019;44:144–52. https://doi.org/10.1016/j.breast.2019.02.001 

    45. Zagalaz-Anula N, Mora-Rubio MJ, Obrero-Gaitán E, et al. Recreational physical activity reduces breast cancer recurrence in female survivors of breast cancer: A meta-analysis. European Journal of Oncology Nursing 2022;59:102162. https://doi.org/10.1016/j.ejon.2022.102162 

    46. Shreves AH, Small SR, Walmsley R, et al. Amount and intensity of daily total physical activity, step count and risk of incident cancer in the UK Biobank. Br J Sports Med 2025;59:839–47. https://doi.org/10.1136/bjsports-2024-109360 

    47. Department of Health and Social Care. Physical activity guidelines: UK Chief Medical Officers’ report 2019. https://www.gov.uk/government/publications/physical-activity-guidelines-uk-chief-medical-officers-report (accessed May 29, 2026) 

woman swimming in the sea