Psychosocial correlates of physical activity in white and African-American girls.
OBJECTIVE
To evaluate the relative utility of the Theory of Reasoned Action (TRA) and the Theory of Planned Behavior (TPB) in explaining intentions and physical activity behavior in white and African-American eighth-grade girls.


METHODS
One-thousand-thirty white and 1.114 African-American eighth-grade girls (mean age 13.6 +/- 0.7 years) from 31 middle schools in South Carolina completed a 3-day physical activity recall and a questionnaire assessing attitudes, subjective norms, perceived behavioral control, self-efficacy, and intentions related to regular participation in moderate-to-vigorous physical activity (MVPA).


RESULTS
Among Whites, 17% of the variance in intentions was contributed by subjective norms and attitude, with intentions accounting for 8% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 40% and 10% of the variance, respectively. Among African-Americans, subjective norms and attitude accounted for 13% of the variance in intentions, with intentions accounting for only 3% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 28% and 5% of the variance, respectively.


CONCLUSIONS
The results provided limited empirical support for the TPB among white adolescent girls; however, our findings suggest that the planned behavior framework has limited utility among African-American adolescent girls. The relatively weak link between intentions and MVPA observed in both population groups suggest that constructs external to the TPB may be more important mediators of physical activity behavior in adolescent girls.
Trost
Stewart G
SG
School of Human Movement Studies, The University of Queensland, Brisbane, Australia. strost@hms.uq.edu.au
Pate
Russell R
RR
Dowda
Marsha
M
Ward
Dianne S
DS
Felton
Gwen
G
Saunders
Ruth
R
D000293:Adolescent; D000294:Adolescent Behavior / Q000208:ethnology*; D001741:Black or African American / Q000523:psychology*; D000704:Analysis of Variance; D001294:Attitude to Health / Q000208:ethnology; D015444:Exercise / Q000523:psychology*; D005260:Female; D015438:Health Behavior / Q000208:ethnology*; D006801:Humans; D007389:Internal-External Control; D009042:Motivation; D011582:Psychological Theory; D012044:Regression Analysis; D020377:Self Efficacy; D011795:Surveys and Questionnaires; D044465:White People / Q000523:psychology*