A Test of the Theory of Planned Behavior to Explain Physical Activity in a Large
Population Sample of Adolescents From Alberta, Canada
Discussion
This research appears to be the largest TPB study on youth
conducted with a representative sample. Overall, our results
support the TPB with statistically significant values for all construct
pathways. Perceived behavioral control and intention accounted
for 43% of the variance in behavior for the overall sample.
Attitude, subjective norm, and perceived behavioral control
explained 59% of the variance for intention. These results are
generally consistent with PA-TPB literature in both adolescent
and adult populations [9,10].
Differences existed in the strength of associations between
TPB constructs when comparing the gender-specific models.
However, for both genders, perceived behavioral control was
the strongest correlate of behavior, and attitude was the strongest
correlate of intention. This highlights the importance of
practitioners/teachers to provide enjoyable activities and
strategies to enhance adolescents’ confidence to adopt and
sustain regular PA.
Finally, the assumptions for mediation were satisfied for all
three TPB constructs (i.e., attitude, subjective norm, perceived
behavioral control). Although the sizes of the mediated effects
were small, they did have important implications at the population
level.