Reinforcing value of physical activity as a determinant of child activity level.

This study examined whether the relative reinforcing value of physical activity (RRVPA) measured in the laboratory predicted physical activity measured in the natural environment in 32 6-11-year-old children. RRVPA correlated with physical activity level (r = .42, p < .05), and contributed to the prediction of physical activity level along with child obesity. RRVPA was related to the number of moderate to vigorous physical activity exercise bouts (r = .35, p < .05), not to the duration of those bouts. These results suggest that RRVPA is a determinant of child physical activity level, and that it may be naturally more reinforcing for children to engage in multiple, short exercise bouts than fewer, more extended bouts.