The impact of parenthood on Canadians' objectively measured physical activity: an examination of cross-sectional population-based data.

Background: Parenthood has been associated with declines in leisure-time exercise and moderate-to-vigorous physical activity (MVPA), but less is known about its impact on sedentary time and light-intensity activity. Although the health benefits of MVPA are well established, a growing body of research has been showing that even after controlling for MVPA levels, a detrimental dose-response association exists between sedentary time and adverse health outcomes and a beneficial dose-response association exists for light-intensity activity.

Methods: This study examined the impact of parenthood, the number of children in the home, and the age of the youngest child on objectively measured physical activity (i.