Guest Blog: How keeping physically active cuts your risk of cancer

More than 350,000 people are diagnosed with cancer each year in the UK. Advances in medical science mean that half of all these new cases will be successfully treated but perhaps the biggest surprise is four in ten (40%) are preventable.

Some of the ‘lifestyle’ risk factors for cancer such as smoking are well known. However, a new and rapidly growing body of research suggests the amount of regular physical activity we get also makes a huge difference to our cancer risk.

For example, a recent large scale study reported on by the BBC found that among people who habitually cycle to work the incidence of cancer fell by 45%.

The charity Cancer Research UK conducts an annual review of the scientific evidence linking cancer to physical activity. It finds strong evidence that the amount of movement we build into our lives (or lack of it) directly impacts our propensity to developing bowel, womb and breast cancer.

The same review finds that physical activity also appears to reduce the risk of lung and prostate cancer, although the evidence here is not yet strong enough to be certain.

Why should exercise make a difference?

For each cancer type, physical activity has different impacts and not all are fully understood by scientists. However, the following benefits of physical activity are all thought to play a role:

• Lowering insulin and estrogen levels in the blood stream
• Cutting the risk of unnecessary weight gain – especially in middle age
• Reducing inflammation associated with long periods of sitting
• Boosting the metabolism and immune systems
• Improving digestion and the processing of what we eat

What types of physical activity reduce the risk of cancer?

There are two golden rules to follow here: the physical activity you pursue needs to raise your heart rate and it needs to be sustained over time.

The NHS and other expert bodies recommend a minimum of 150 minutes of ‘moderate’ physical activity a week for all adults or 75 minutes of ‘vigorous’ physical activity.

Moderate physical activity, such as brisk walking, is defined as activity that causes you to breath harder. A good test is that you can talk but would struggle to sing. Vigorous physical activity, such as stair climbing or jogging, drives your heart and breathing fast enough to make saying more than a few words difficult without catching your breath.

Because the long term benefits of physical activity accumulate over years rather than months, experts stress the importance of picking activities that you can build into daily life.

For example, training for a marathon can be good for you but it’s not something you are likely to be able to keep up for a lifetime. Much better is to aim for sustainable activities – things that become second nature and you do as a matter of habit. Great examples include:

Active travel
• Walking, cycling or jogging to work
• Getting off the bus or train a stop early
• Making a rule of using public transport rather than taxis or cars where possible

Active work
• Always taking the stairs rather than a lift or escalator
• Making all one-to-one meetings walking meetings
• Getting involved with in-work exercise classes where possible

Active leisure
• Joining dance, walking, fitness or sports groups
• Making all your holidays ‘activity’ based – think walking, sightseeing, skiing, surfing
• Dog walking (if not yours, then a friends!)

Never forget how much time you spend at work

Many people see physical activity as something for their free time. This is a big mistake. The bulk of many people’s waking hours will be spent at work, and in many modern occupations the vast majority of that time will be desk-based and sedentary.

All the more important therefore to lobby your employer to implement evidence based corporate wellness programme so that they can build a culture of wellness in the workplace.


About the Author

Seth Valchev is a workplace health and physical activity specialist for StepJockey.