Programmed aerobic exercise can alter whole-body protein utilisation in healthy children, a recent US study reveals. Scientists at the Department of Nutritional Sciences, University of Connecticut set out to examine the effects of programmed aerobic exercise on protein metabolism in children. Boys and girls walked between 3.2 and 6.4 km per day for 6 weeks. Criterion measured before and after the exercise included anthropometric data, dietary assessment, nitrogen balance, nitrogen flux (Q), protein synthesis (PS), protein breakdown (PB) and net protein balance. Energy and protein intakes were constant throughout the study. After the walking program although there were no significant changes in body weight, fat-free mass or percentage of body fat height actually increased. The authors of the study stress that longitudinal studies are required to further examine changes in protein metabolism associated with increased physical activity in children. Full findings are published in the Journal of Nutrition. 2001;131:2659-2663.