Van Hout assessed the perception of social context and activity scales of adolescent substance abusers following participation in a physical activity intervention during residential drug treatment.1  The increase in perception of social context value was measured by increased social interaction, group identification, trust, co-operation and social growth. The increase in perception of activity value was measured by increased enjoyment, self-efficacy, skill acquisition and confidence. The sample (n=47) was assessed on entry to treatment, on completion of treatment, at six weeks after treatment and at six months after treatment, using mean, standard deviation, and t-tests.