The results of these small group studies constitute an interesting and useful
frame of reference interpreting the findings of population surveys like the
NCYFS-I. The global conclusion of NCYFS-I was that U.S. adolescents participate
in about 100 minutes (1.6 hours) of physical activity per day, a value that
is about 67% greater than the approximate median time in moderate to vigorous
activity (1.0 hour) as observed in the small group studies.