SA1) evaluate among 80 4th and 5th grade ethnic minority children the feasibility of a pilot cluster RCT of a Bicycle Train program for (a) recruiting participants for a planned full-scale cluster RCT (b) promoting their participation, and (c) identifying barriers/facilitators to their participation; and SA2) validate algorithms examining concurrent accelerometry and global positioning system (GPS) data to identify and measure children's physical activity intensity and duration while cycling compared to the criterion standards of heart rate monitoring and direct observation