The Finnish study included 2,560 men, aged 42 to 61, whose leisure-time physical activity was assessed over one year. None of the men had a history of cancer, according to the report published online July 28 in the British Journal of Sports Medicine.

During an average follow-up of 16 years, 181 of the men died from cancer. Those who engaged in moderate- to high-intensity exercise for at least 30 minutes a day were 50 percent less likely to develop cancer compared with the other men.

The researchers found that an increase of 1.2 metabolic units (oxygen consumption) was related to a decreased risk of cancer death, especially in lung and gastrointestinal cancers, after they took into account factors such as age, smoking, alcohol consumption, body mass index, and fiber/fat intake.

"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," the study authors wrote in a news release.

More information

The U.S. National Cancer Institute has more about cancer prevention.

SOURCE: BMJ Specialist Journals, news release, July 28, 2009

-- Robert Preidt