Research has shown that exercise can not only help to prevent cancer, it can also help you have a better quality of life while you’re in cancer treatment, and can decrease your chances of getting cancer again.
But if you’re the one going through cancer treatment, exercising might well be the last thing on your mind. So to help you make sense of the research, we’ve gathered the facts on exercising and cancer, as well as some handy exercise ideas to help you be a little bit more active, even when you’re feeling unwell.
The facts – exercise and cancer prevention
It’s hard to pick up a newspaper or scroll through the internet these days without someone mentioning a new “miracle” cancer prevention strategy. So when headlines claim that “exercise prevents cancer”, it may seem too good to be true. And, to a certain extent, it is. Even professional athletes can be diagnosed with cancer, so regular exercise is no guarantee of “immunity”, just as being a non-smoker isn’t a guarantee that someone won’t get lung cancer. (In fact, up to 15% of lung cancer diagnoses are in people who have never smoked a cigarette.)
However, just like being a non-smoker, exercising regularly can help to decrease your risk of certain cancers. Research has shown particularly strong links between keeping active and a lower risk of breast, bowel and womb cancers, and Cancer Research UK estimates that about 3,400 cases of cancer in the UK each year could be prevented by regular moderate exercise. So even if you’ve never been the active type, there’s certainly a lot of reasons to give it a go.
How does exercise prevent cancer?
When it comes to the science of exercise and cancer, there are a few bodily processes at work. Firstly, regular moderate exercise has been shown to reduce levels of certain hormones in your body, including two which play a role in cancer: insulin and oestrogen. One of insulin’s functions is to turn on signals that tell your cells to multiply. Cancer develops when cells multiply out of control, so reducing insulin levels could help to prevent this.
Oestrogen has also been found to play a role in the development of certain cancers, including breast and womb cancers. Lowering oestrogen levels through exercise could therefore also help to prevent these cancers from developing. These theories are backed up by some impressive statistics (available on Cancer Research UK). One 31-study analysis suggests that for every 2 hours a week a woman spends doing moderate to vigorous activity, the risk of breast cancer falls by 5%. Another study found that exercising regularly after going through the menopause can reduce breast cancer risk by 10% – even in women who weren’t previously active at all.
The role of exercise in preventing bowel cancer is somewhat different. Essentially, by keeping your exercise regular, you help to keep your bowels regular too. When processing your food, your digestive system takes the parts that are useful for the body, and “throws away” the parts it doesn’t want; difficult-to-digest foods, and harmful chemicals such as those released when you eat alcohol or red meat. This waste is then passed through your bowels – and the longer these harmful chemicals spend in contact with the inside lining of your bowels, the more likely it is that the lining might become inflamed. Repeated inflammation of the same area can lead to mistakes in how the cells multiply, which is how some cancers can develop. So staying active can help to keep your food moving at a healthy pace, and decrease or prevent the bowel inflammation that can lead to cancer.
Should I exercise during cancer treatment?
Prevention is important, but if you’re already going through cancer, exercise might seem like more of a challenge than ever. The side effects of treatment, as well as the symptoms of cancer itself, may leave you low on energy, in pain or feeling sick – so it’s completely normal if daily exercise lands fairly close to the bottom of your priorities list. However, the health benefits of moderate activity don’t just get “cancelled out” by cancer. In fact, all the evidence points to staying active as a helpful tool in coping with chemotherapy, radiotherapy and other forms of cancer treatment.
One of the main benefits of exercise during cancer treatment is its effect on your mood. Our community often tells us that life with cancer feels just as much a mental struggle as a physical one. Research has shown that just four weekly half hour exercise sessions can help to reduce feelings of anxiety and depression in people with cancer. And when up to 4 out of 10 women are depressed a year after their diagnosis (we couldn’t find the figures for men, but we suspect they may be similar), looking after your mood and mental health is a really important aspect of recovery.
Another common side effect of most cancer treatments is fatigue. It’s likely that at some point during your treatment, you may feel very low on energy, and even normal daily tasks might become quite tiring. Several studies have shown that sticking to a routine of regular gentle exercise can actually help to reduce this fatigue, which is really encouraging. Once you manage to get over the first hurdle of getting out of bed and going for a walk, or even just pottering around the house or garden, it seems that you might actually feel less tired in the long run. Women who have gone through the menopause and are unable to take hormone replacement therapy due to a previous cancer diagnosis may also benefit from weight-bearing exercise such as walking, rowing, or even weightlifting, which can help to keep bones healthy and combat osteoporosis.
Cancer and exercise guidelines
At this point you might be thinking something along the lines of, “I’m not exactly ready to join the gym just yet – I can barely get out of bed!” And quite right too! If you’re not used to exercising, or you’re going through cancer, the last thing you want to do is over-exert yourself. Plus, if you’ve never had much of an exercise routine before, joining a gym or training for a marathon might not be a realistic goal to start off with.
We know every body is different, and that’s why it’s crucial to talk to your doctor before you decide to change your exercise habits during cancer treatment. They will be able to recommend types of exercise that might work for you, and other types that you should avoid. However, there are a few things almost everybody can do to increase their activity level – all at your own pace. So far we’ve explained how regular, moderate exercise can help you to prevent or cope with cancer. But what exactly is this “moderate exercise”?
Exercise for the absolute beginner
Firstly it’s important to recognise that, especially if you have cancer, one person’s “moderate” is another person’s “absolutely no way I can manage that today”. That said, there are some guidelines for exercising with cancer which have been agreed on by medical professionals. It might surprise you to hear that in fact, the guidelines for cancer patients are no different to those for people who don’t have cancer.
If you’re able to, doctors advise around 30 minutes of moderate activity such as walking, 5 days a week. If that sounds difficult to achieve, try building up slowly over a couple of weeks. You could start by walking for five or ten minutes around your house or garden, or around the ward if you’re in hospital. Maybe the next day you could do two ten minute walks, then eventually move up to three. By doing a little bit more every day, even a single extra minute, you can gradually build up your strength and your confidence.
If walking doesn’t sound like your cup of tea, don’t worry – there are plenty of other ways to get your daily dose of “moderate exercise”. Cycling can be a great way to get your thirty minutes, and if you have neuropathy that affects your balance or the feeling in your limbs, an exercise bike is a great way to exercise safely. Other activities that count as moderate exercise include gardening, housework, and even just having a good old fashioned boogie. As long as you’re weeding, hoovering, or shaking your thing for thirty minutes, five times a week, you’re right on target for being more active.
Finally, one bit of exercise advice that most doctors will give is to make your exercise a habit. If it’s something that you only do once in a while, you’re less likely to stick to it, and you won’t get the health benefits either. A good routine is all about fitting exercise around your life, so going for a walk with a friend every Wednesday afternoon, or picking up the paper from the shop down the road every day, is the best way to keep your activity levels consistent.
We’d love to hear your experiences of exercising with cancer – whether you ran a marathon or just started taking the stairs more often, let us know how exercise worked (or didn’t work) for you. You can share your stories with us and our 40,000-strong community in the comments below, or on our Facebook or Twitter pages.