Intensive exercise may reduce risk of cancer
People who lead an active lifestyle with regular intensive exercise are less likely to die from cancer, a study by Finnish scientists suggests.
Researchers at the Universities of Kuopio and Oulu studied 2,560 men between the ages of 42 and 61 years, none of whom had ever been diagnosed with cancer.
Participants' levels of physical activity were recorded over a 12-month period and the men were then followed-up for an average of 16 years.
During that time, 181 of the men died from cancer, with the most common forms being gastrointestinal cancers - which include oesophagus, stomach and bowel cancers - lung cancer, prostate cancer, brain tumours and lymphoma.
The researchers calculated that walking has an average intensity - in terms of oxygen consumption - of 4.2 metabolic units; jogging was 10.1 units; swimming 5.4; gardening 4.3; and cycling to work 5.1. They then worked out each man's average activity levels. On average, men taking part in the study tended to have an activity intensity of 4.5 MET for 462 minutes per week. The researchers discovered that men who exercised at moderate to high-intensity - over 5.2 MET - for at least 30 minutes a day were half as likely to develop cancer as those who did not.
However, over a quarter of the men did less than 30 minutes of exercise per day.
Analysis also revealed that an increase of 1.2 MET was associated with a decrease in the risk of dying from cancer, particularly cancers of the lung and gastrointestinal tract.
Writing in the British Journal of Sports Medicine, the researchers concluded: "The intensity of leisure-time physical activity should be at least moderate so that beneficial effect of physical activity for reducing overall cancer mortality can be achieved."
Jessica Harris, Cancer Research UK's health information officer, said: "We know that being physically active can reduce the risk of breast and bowel cancer, and this study tells us that keeping active can also lower the odds of dying from cancer.
"That is why Cancer Research UK recommends doing at least half an hour's moderate activity on five days a week - and the more active you are, the greater the benefits."
Laukkanen, J., Rauramaa, R., Makikallio, T., Toriola, A., & Kurl, S. (2009). Intensity of leisure-time physical activity and Cancer mortality in men British Journal of Sports Medicine DOI: 10.1136/bjsm.2008.056713