From feeling that post-workout euphoria to fitting into your favourite jeans, there are many reasons why we exercise.
But did you know that being active can also help lower your risk of cancer?
Some cancers, like bowel and breast cancer, have been directly linked to a lack of movement. And being a healthy weight can also reduce your likelihood of developing cancer. With this in mind, it’s important to keep moving and find a form of exercise we enjoy.
How does exercise lower the risk of cancer?
Researchers are still working to determine exactly how exercise helps to lower the risk of cancer. But they have some strong theories that might explain how being active protects the body.
Reduction in insulin resistance
Physical activity helps muscles absorb oxygen and nutrients more effectively.
When we exercise, our muscles burn lots of blood sugar, or ‘glucose’. We get glucose when our bodies break down the carbohydrates that we eat or drink.
Insulin, a hormone made by the pancreas, helps cells absorb glucose and use it for energy. It also tells the liver to store glucose so it can be used when the body needs it most.
‘Insulin resistance’ happens when the cells of the body stop responding properly to insulin. This makes it more likely that glucose will build up in the blood and cells are unable to absorb it. It can cause diabetes and other health conditions, including bowel, breast and womb (uterine or endometrial) cancer.
Reduction in inflammation
Inflammation in the body can also lead to breast, bowel and womb cancer, and it’s thought that exercise can help reduce this.
Inflammation is the body’s way of protecting itself from infection, illness or injury, and involves the production of white blood cells, immune cells and other substances.
Sometimes the body’s inflammatory response persists for months or even years if the immune system fails to fix the problem. It can also stay active even after the initial problem has been eliminated. This can eventually start damaging healthy cells, tissues, and organs.
A female hormone called oestrogen can sometimes stimulate cancer cells and cause them to grow. Researchers think exercise may play a role in reducing oestrogen levels and lowering the risk of both breast and womb (uterine or endometrial) cancer in women.
Exercise can stimulate digestion and reduce the time it takes for food to move through the intestine. This may reduce the risk of bowel cancer, however more data is required to support this theory.
Can being overweight increase my risk of cancer?
Being overweight or obese is the second largest preventable cause of cancer in the UK and has been linked to 13 different types of cancer.
Issues like inflammation, insulin resistance and high levels of oestrogen are all associated with being overweight.
Being overweight can cause the body to be in a constant low-level state of inflammation, which is different to the healthy short-term inflammatory response of our bodies to help with damaged tissue. Long-term inflammation promotes the growth and dividing of new cells at a higher rate, and over a long period of time this can cause cancer.
Fat cells release significant amounts of oestrogen – this can make cells in the breast and womb divide faster increasing the risk of cancer, and they can also cause cells to become resistant to insulin.
Along with a healthy diet, exercise can help maintain a healthy weight.
What’s the picture like in Yorkshire?
Each year in Yorkshire, 155 new cases of cancer are directly linked to a lack of regular physical activity.
And 1,947 cases are linked to being overweight – this represents 6% of all cancers diagnosed in our region.
The Government recommends all adults do at least 150 minutes of moderate intensity activity each week, or 75 minutes of vigorous intensity activity if you are already active, or even shorter durations of very vigorous activity such as sprinting or weight exercises - or a combination of all three.
Those aged 19 to 64 are also advised to do strengthening activities that work all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms) on at least two days a week. Older adults are advised to do activities that improve strength, balance and flexibility on at least two days a week.
People in Yorkshire are less likely to be physically active when compared to the average in England .
So there’s lots of work to be done to raise awareness of exercise and how it can lower the risk of cancer.
Want to get active but not sure how?
Here are some websites that could help you get moving and stay motivated.
More information about the Government’s guidelines
NHS information and videos
NHS Fitness Studio - 24 instructor-led videos across aerobics exercise, strength and resistance, and pilates and yoga categories.
10 minute workouts - Equipment-free fitness routines to fit into your daily schedule
One You Home Workout Videos – Cardio, strengthening and cool down videos
Sitting exercises - Gentle sitting exercises to improve your mobility
Balance exercises – Simple balance exercises to improve your mobility
Flexibility exercises - Flexibility exercises that can be done at home
Strength exercises – Strength exercises to build muscle
Couch to 5K – A nine-week programme to help you reach 5K
Further information and videos
The Body Coach TV – Video workouts for all ages from fitness coach Joe Wicks
30 days of yoga – A series of yoga videos for all-levels by international yoga teacher Adriene Mishler
Strava Art – For runners who are looking to get creative
This Girl Can – A one-stop shop from Sport England for women who want to get active
Stay in, work out – Tips, advice and guidance on how to keep or get active in and around your home from Sport England.
Murphy N, Cross AJ, Abubakar M, Jenab M, Aleksandrova K, Boutron-Ruault M-C, et al. (2016) A Nested Case–Control Study of Metabolically Defined Body Size Phenotypes and Risk of Colorectal Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC). PLoS Med 13(4): e1001988. https://doi.org/10.1371/journal.pmed.1001988
Ho, G. Y., Wang, T., Gunter, M. J., Strickler, H. D., Cushman, M., Kaplan, R. C., Wassertheil-Smoller, S., Xue, X., Rajpathak, S. N., Chlebowski, R. T., Vitolins, M. Z., Scherer, P. E., & Rohan, T. E. (2012). Adipokines linking obesity with colorectal cancer risk in postmenopausal women. Cancer research, 72(12), 3029–3037. https://doi.org/10.1158/0008-5472.CAN-11-2771
Zhou, B., Shu, B., Yang, J. et al. C-reactive protein, interleukin-6 and the risk of colorectal cancer: a meta-analysis. Cancer Causes Control 25, 1397–1405 (2014). https://doi.org/10.1007/s10552-014-0445-8
Brown, K.F., Rumgay, H., Dunlop, C. et al. The fraction of cancer attributable to modifiable risk factors in England, Wales, Scotland, Northern Ireland, and the United Kingdom in 2015. Br J Cancer 118, 1130–1141 (2018). https://doi.org/10.1038/s41416-018-0029-6
Cancer Data, https://www.cancerdata.nhs.uk/
Deng, T., Lyon, C. J., Bergin, S., Caligiuri, M. A., & Hsueh, W. A. (2016). Obesity, inflammation, and cancer. Annual Review of Pathology: Mechanisms of Disease, 11, 421-449.