Media coverage of a recent BJSM article underscores the important role of physical activity in the prevention of cancer. The news headline reads: Brisk exercise ‘cuts cancer death risk. ’

The article refers to  Laukkanen, Rauramaa, Mäkikallio, Toriola, and Kurl’s study that defines “the intensity of leisure-time physical activity required to reduce cancer mortality in a population-based sample of men from eastern Finland.”  2560 middle-aged men who completed a 12-month leisure-time physical activity questionnaire. “Among those who exercised at least 30 minutes per day, the risk of cancer death was clearly decreased according to the mean intensity categories (<3, 3–6, >6 MET) of physical activity.” [Remember one MET is energy use at rest – walking is about 1.5, running about 3].

To summarize the key findings:

• Moderate intensity physical activity is more beneficial than low intensity physical activity in the prevention of premature death from (mainly lung and gastrointestinal) cancer in men
• The total amount of physical activity is more important than the type, frequency, or duration of a single session or intensity of physical activity

Laukkanen et al. do mention the difficulty in isolating physical activity as an independent risk factor –genetic and other lifestyle factors also influence cancer aetiology. Still, results are promising enough to suggest the benefits of 30 minutes of physical activity a day. As clinicians, this is useful to communicate to those sedentary individuals intimidated by thinking they need to run marathons to improve their health.

Need more evidence on the benefits of physical activity?

See: Blair, S. 2009. Physical inactivity: the biggest public health problem of the 21st century. BJSM. 43:1-2

Sanchez-Villegas A, Ara I, Dierssen T, de la Fuente C, Ruano C, Martínez-González MA. 2011 Physical activity during leisure time and quality of life in a Spanish cohort: SUN (Seguimiento Universidad de Navarra) Project. BJSM. Apr 17. [Epub ahead of print]