People who are more active and exercise harder are less likely to develop cancer and die, suggests research published ahead of print in the British Journal of Sports Medicine.

A higher use of oxygen consumption during physical activity is linked to a reduction in the level of illness in a person and their likelihood of dying from cancer.

Researchers from the universities of Kuopio and Oulu in Finland studied 2,560 men aged between 42 and 61 from eastern Finland with no history of cancer and assessed their leisure time physical activity over a 12-month period.

The men were followed up for around 16 years, on average, and a total of 181 of them had died from cancer. The most common types of cancer death noted were gastrointestinal, lung, prostate, brain and lymphoma.

Existing evidence recommends at least 30 minutes of moderate-intensity physical activity on most days for health promotion and prevention of heart disease. Little is known, however, about what levels of activity are beneficial, if at all, to reduce cancer mortality.

The researchers used a physical activity questionnaire and asked the men participating in the study to record the frequency (number of sessions per month), average duration of the session, and intensity of activity. The intensity of physical activity was measured in metabolic units (MET or metabolic equivalents of oxygen consumption).

Walking was measured as having an average intensity of 4.2 MET, jogging 10.1 MET, swimming 5.4 MET, yard work/gardening/farming 4.3 MET, and bicycling to work 5.1 MET.

The researchers found that average intensity of the men's physical activity was 4.5 MET and the average duration of activity was 462 minutes per week. Just over a quarter of the men (27%) performed exercise for less than 30 minutes a day during leisure time.

An increase of 1.2 metabolic units (oxygen consumption) was related to a decrease in cancer mortality mainly due to lung and gastrointestinal cancers, after the researchers took into account age, alcohol consumption, smoking, body mass index and energy, fibre and fat intake.

Men who exercised to a moderate to high intensity level for at least 30 minutes a day were half as likely to get cancer as those who did not.

The authors say that physical inactivity during a person's lifetime could be a key factor in the person developing cancer. They conclude "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."

"Intensity of leisure-time physical activity and cancer mortality in men."
Br J Sports Med 2009; doi 10.1136/bjsm.2008.056713

Source
British Journal of Sports Medicine