“Higher levels of physical activity, in particular activity of moderate to higher intensities, are prospectively associated with lower levels of fat mass in early adolescence. Interventions to raise levels of physical activity in children are likely to be important in the fight against obesity.”
British and American researchers investigated whether physical activity at age 12 was associated with subsequent adiposity at age 14. They utilized an existing prospective birth cohort study based in the United Kingdom (n= 4150, 1964 boys, 2186 girls). They measured physical activity at age 12 by accelerometry and adiposity at age 14 with dual emission X-ray absortiometry.
They found: “Prospective associations of fat mass at age 14 (outcome) with physical activity at age 12 (exposure) were strong for both total activity (accelerometer counts per min) and for daily amount of moderate-vigorous physical activity (min per day). An extra 15 minutes of moderate-vigorous physical activity per day at age 12 was associated with lower fat mass at age 14 in boys (by 11.9%) and girls (by 9.8%). The proportion of physical activity due to moderate-vigorous physical activity was between 20% and 30% in boys and girls at the two ages.”
This study reinforces the importance of physical activity, especially moderate to high intensity exercise, in addressing the rising tide of adolescent and adult obesity.
BMJ 339:b4544, 26 November 2009 : Prospective associations between objective measures of physical activity and fat mass in 12-14 year old children: the Avon Longitudinal Study of Parents and Children. Chris J Riddoch, Sam D Leary, Andy R Ness, et al.