Critical hours: Physical activity and sedentary behavior of adolescents after school

The present study examined physical activity and sedentary behavior patterns of adolescents between 15.30h and 18.30h. The sample for this study is 1,484 (boys: n = 561; girls: n = 923). Boys and girls reported 21 and 19 min of physical activity and 24 and 26 min of homework respectively during this period. Technology-based sedentary behavior (TV viewing, computer and video game use) was significantly higher in boys than girls (boys = 50 mins; girls = 35 mins; p < .05). The most prevalent behaviors after school are technology-based sedentary behavior, homework and physical activity. During these hours, engagement in physical activity does not appear to displace time spent doing homework. © 2008 Human Kinetics, Inc.