A growing body of evidence supports a link between sedentary behaviour and an increased risk for cancer. The health risk from sedentary behaviour is not influenced by the amount of physical activity a person does, so it is an independent risk factor. Sitting for long periods of time can increase cancer risk, even in people who exercise regularly. Even if you exercise for 30 minutes or more a day, but spend the rest of the day in sedentary activities, you can still be at an increased risk for cancer. It is likely that the longer a person sits, the higher the risk. Higher amounts of sedentary behaviour are associated with an increased risk of colorectal cancer.
Sedentary behaviour refers to activities that need very little physical movement and don't use much energy, such as sitting or lying down for long periods of time. It is often called "too much sitting." Sedentary behaviour is different from not getting enough exercise.
Canadian adults are sedentary for most of their waking hours. For men, 68% of their waking hours are sedentary. Women spend 69% of their waking hours in sedentary activities.
Many Canadians spend a lot of their leisure time in sedentary activities. People are spending more and more time watching TV, using a computer, watching videos and playing online or video games. These screen-based forms of entertainment are examples of activities that usually involve a lot of sitting. Prolonged sitting also occurs with increased time spent in automobiles and sitting in the workplace (occupational sitting).
Researchers recognize sedentary behaviour as a health risk. Sedentary behaviour contributes to weight gain and becoming overweight or obese.