Lifetime Physical Activity and the Risk of Colorectal Cancer: A Population-Based Case-Control Study Using Data from the Newfoundland Colorectal Cancer Registry

Although there is consistent evidence of an inverse association between physical activity and colorectal cancer (CRC), it is unclear whether physical activity has to be lifelong in order to protect against CRC, or whether there are critical time periods in which physical activity is most protective. This thesis investigated the association between recreational physical activities in specific age periods and across the lifetime and CRC risk in data from a population-based case control study (n=1395) in Newfoundland and Labrador. There were no significant associations between recreational physical activity at any age period or across the lifetime. Lack of association with activity in early adulthood is consistent with other studies in which this has been investigated. Lack of association in later life and across the lifetime may in part be explained by low levels of recreational physical activity, with only 30% of participants meeting World Cancer Research Fund cancer prevention recommendations