Gender differences in physical activity in older children and adolescents: the central role of organized sport.

Previous studies have generally had limited success in accounting for gender differences in leisure time physical activity. Based on a representative national survey of 3270 Icelandic 6th, 8th and 10th grade students, the study found that girls' lower enrollment in organized sport clubs fully accounts for gender differences in frequency of overall physical activity, and largely accounts for gender differences in frequency of strenuous activity, and weekly hours of overall and strenuous activity (enrollment hypothesis). Furthermore, girls' higher sport club withdrawal rate accounted for a small but significant part of the gender difference in weekly hours of overall activity and frequency of strenuous activity (withdrawal hypothesis). No evidence was found to suggest that different activity levels of boys and girls enrolled in the clubs affected gender differences in levels of overall or strenuous physical activity (activity differential hypothesis). Other independent variables, i.e., perceived importance of sport achievement, sport and exercise related instruction, physical education experiences, and social modeling, did not significantly affect observed gender differences beyond the sport club variables. The meaning of the results, and their implications for gender disparities, health promotion, and future research are discussed. Copyright 2002 Elsevier Science Ltd.