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Educating the Student Body: Taking Physical Activity and Physical Education to School
Relationship to Growth, Development, and Health
135
length and duration of physical activity for improving mental health remain
unclear, however. Regular exercise is associated with improved mood, but
results are inconsistent for the association between mood and medium- or
long-term exercise (Dua and Hargreaves, 1992; Slaven and Lee, 1997;
Dimeo et al., 2001; Dunn et al., 2001; Kritz-Silverstein et al., 2001; Sexton
et al., 2001; Leppamaki et al., 2002; Peluso and Guerra de Andrade, 2005).
Studies often do not specify the frequency and duration of physical activ-
ity episodes; among those that do, interventions ranged from 6 weeks to
2 years in duration. In their meta-analysis, Ahn and Fedewa (2011) found
that, comparing interventions entailing a total of more than 33 hours,
20-33 hours, and less than 20 hours, the longer programs were more effec-
tive. Overall, the lack of reporting and the variable length and duration of
reported interventions make it difficult to draw conclusions regarding dose
(Ahn and Fedewa, 2011).
In addition to more structured opportunities, naturally occurring
physical activity outside of school time is associated with fewer depres-
sive symptoms among adolescents (Penedo and Dahn, 2005). RCTs have
demonstrated that physical activity involving entire classrooms of stu-
dents is effective in alleviating negative mental health outcomes (Ahn and
Fedewa, 2011). Non-RCT studies have shown individualized approaches
to be most effective and small-group approaches to be effective to a more
limited extent (Ahn and Fedewa, 2011). Interventions have been shown
to be effective in improving mental health when delivered by classroom
teachers, physical education specialists, or researchers but may be most
effective when conducted with a physical education specialist (Ahn and
Fedewa, 2011). Many physical activity interventions include elements of
social interaction and support; however, studies to date have been unable to
distinguish whether the physical activity itself or these other factors account
for the observed effects on mental health (Hasselstrom et al., 2002; Hallal
et al., 2006). Finally, a few trials (Larun et al., 2006; Biddle and Asare,
2011) have compared the effects of physical activity and psychosocial inter-
ventions, finding that physical activity may be equally effective but may not
provide any added benefit.
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