Physical activity and sedentary behaviour in youth

A low level of daily physical activity is one of the main causes for the avoidable burden of noncommunicable disease and premature death (Lee et al., 2012). Sedentary behaviour (low-energy activities performed while sitting during waking time, such as TV viewing, computer use, reading) is not synonymous with physical inactivity. Recent research has shown that highly active children can also participate in high levels of sedentary behaviour (De Bourdeaudhuij et al., 2013; te Velde et al., 2007). In adults, excessive sedentary behaviour has been shown to have adverse health effects, independent of moderate to vigorous physical activity (Grontved and Hu, 2011; Proper et al., 2011; van der Ploeg et al., 2012). Physical activity levels decline and sedentary behaviour increases throughout childhood into older age (Van Mechelen, et al., 2000). Therefore, promoting physical activity and limiting sedentary behaviour are important health policy priorities in Europe and beyond.