Gwen A. Felton

Measuring enjoyment of physical activity in adolescent girls

BACKGROUND Enjoyment has been implicated as a determinant of physical activity among youth, but advances in understanding its importance have been limited by the use of measures that were not adequately validated. The present study examined: (1) the factorial validity of the Physical Activity Enjoyment Scale (PACES), and (2) the construct validity of PACES scores. METHODS Adolescent girls (N=1797), who were randomly assigned to calibration (n=899) and cross-validation (n=898) samples, completed the PACES and measures of factors influencing enjoyment of physical education, physical activity, and sport involvement. The factorial validity of the PACES and the measure of factors influencing enjoyment of physical education was tested using exploratory and confirmatory factor analysis. The hypothesized relationships among the measures were tested using structural equation modeling. RESULTS Unidimensional models fit the PACES and the measure of factors influencing enjoyment of physical education in the calibration and cross-validation samples. The hypothesized relationships between the PACES and the measures of factors influencing enjoyment of physical education, physical activity, and sport involvement were supported in the entire sample, were similar in African-American and Caucasian girls, and were independent of physical fitness. CONCLUSIONS Evidence of factorial validity and convergent evidence for construct validity indicate that the PACES is a valid measure of physical activity enjoyment among adolescent girls, suitable for use as a mediator variable in interventions designed to increase physical activity.

Enjoyment mediates effects of a school-based physical-activity intervention.

PURPOSE The study evaluated whether targeted changes in factors influencing enjoyment of physical education (PE), physical activity enjoyment, and self-efficacy beliefs about participating in physical activity mediated the effect of the Lifestyle Education for Activity Program (LEAP) intervention on participation in physical activity. METHODS High schools (N=24) paired on enrollment size, racial composition, urban or rural location, and class structure were randomized into control (N=12) or experimental (N=12) groups. Of the 4044 girls enrolled and eligible, 2087 (51.6%) participated in the measurement component of the study. There were 1038 girls in the control group and 1049 girls in the experimental group. INTERVENTION LEAP was a comprehensive school-based intervention emphasizing changes in instruction and school environment designed to increase physical activity among black and white adolescent girls. It was organized according to the Coordinated School Health Program and included a PE component with core objectives of promoting enjoyment of PE, physical activity enjoyment, and self-efficacy. RESULTS Latent variable structural equation modeling indicated that: 1) the intervention had direct, positive effects on physical activity and factors influencing enjoyment of PE, which subsequently explained the effects of increased physical activity enjoyment and self-efficacy on increased physical activity; and 2) an additional, indirect effect of physical activity enjoyment on physical activity operated by an influence on self-efficacy. CONCLUSIONS Increases in enjoyment partially mediated the positive effect of the LEAP intervention. To our knowledge, we have provided the first experimental evidence from a randomized controlled trial linking increased enjoyment with increased physical activity among black and white adolescent girls.

Promotion of Physical Activity Among High-School Girls: A Randomized Controlled Trial

OBJECTIVES Many adolescent girls fail to meet national guidelines for physical activity, and the prevalence of obesity is increasing among this group. Our study examined the effects of a comprehensive school-based intervention on physical activity among high-school girls. METHODS A group-randomized controlled field trial was conducted at 24 high schools. A school-based sample of 2744 girls (48.7% African American, 46.7% White) participated in a measurement protocol when they were in eighth and then ninth grade. A comprehensive physical activity intervention was designed to change the instructional program and the school environment to increase support for physical activity among girls. RESULTS At follow-up, 45% of girls in the intervention schools and 36% of girls in the control schools reported vigorous physical activity during an average of 1 or more 30-minute time blocks per day over a 3-day period. CONCLUSIONS A comprehensive school-based intervention can increase regular participation in vigorous physical activity among high-school girls.

Physical Self-Concept and Self-Esteem Mediate Cross-Sectional Relations of Physical Activity and Sport Participation With Depression Symptoms Among Adolescent Girls

The authors tested whether physical self-concept and self-esteem would mediate cross-sectional relations of physical activity and sport participation with depression symptoms among 1,250 girls in 12th grade. There was a strong positive relation between global physical self-concept and self-esteem and a moderate inverse relation between self-esteem and depression symptoms. Physical activity and sport participation each had an indirect, positive relation with global physical self-concept that was independent of objective measures of cardiorespiratory fitness and body fatness. These correlational findings provide initial evidence suggesting that physical activity and sport participation might reduce depression risk among adolescent girls by unique, positive influences on physical self-concept that operate independently of fitness, body mass index, and perceptions of sports competence, body fat, and appearance.

Examining Social-Cognitive Determinants of Intention and Physical Activity Among Black and White Adolescent Girls Using Structural Equation Modeling

Structural equation modeling was used to evaluate components within the theories of reasoned action (TRA), planned behavior (TPB), and self-efficacy (SET) for understanding moderate and vigorous physical activity among 1,797 Black and White adolescent girls. Modest to strong support was provided for components of TPB and SET; weak support was provided for components of TRA. Perceived behavioral control was related to vigorous physical activity. Self-efficacy was related to moderate and vigorous physical activity, and it accounted for the effect of intention on physical activity. The observed relationships were similar between Black and White girls. Self-efficacy and perceived behavioral control are independent influences on physical activity among Black and White adolescent girls and warrant study as potential mediators in physical activity interventions.

Psychosocial Correlates of Physical Activity in White and African-American Girls

PURPOSE 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.

Process evaluation results from a school- and community-linked intervention: the Trial of Activity for Adolescent Girls (TAAG)

Process evaluation is a component of intervention research that evaluates whether interventions are delivered and received as intended. Here, we describe the process evaluation results for the Trial of Activity for Adolescent Girls (TAAG) intervention. The intervention consisted of four synergistic components designed to provide supportive school- and community-linked environments to prevent the decline in physical activity in adolescent girls. Process evaluation results indicate that the intervention components were delivered from intervention staff to teachers with high fidelity (84–97%) to the protocol and with lower fidelity (range: 18–93%) from teachers to students. Physical activity programs for girls, a unique feature of the TAAG intervention, increased from a mean of 10 programs per school to a mean of 16 and 15 in years 1 and 2, respectively, in intervention schools, with no change in control schools. These findings suggest that a multicomponent school- and community-based physical activity intervention can be delivered with fidelity and result in a middle school environment that supports physical activity for girls.

Self-motivation and physical activity among black and white adolescent girls.

PURPOSE The psychometric properties of the Self-Motivation Inventory for children (SMI-C) were established using tests of factorial validity, factorial invariance, latent mean structure, and predictive validity. METHODS Adolescent girls from two cohorts (N = 955 and 1797) completed the SMI-C and measures of physical activity, team sport involvement, cardiorespiratory endurance, and body fatness in the 8th grade; participants in cohort 2 ( N= 1658) also completed the measures 1 yr later in the 9th grade. The data were analyzed with exploratory and confirmatory (CFA) factor analysis and structural equation modeling (SEM). RESULTS The 20-item SMI-C was best represented by a single substantive factor, but there were method effects among the negatively worded items. CFA indicated that a single-factor model fit the nine positively worded items and exhibited strong evidence of cross-validity and factorial invariance between races and across 1 yr; there were no differences in latent means between black and white girls. SEM indicated that the nine-item SMI-C had direct effects on moderate (gamma(11) = 0.16) and vigorous (gamma(21) = 0.22) physical activity and team sport involvement (gamma(31) = 0.29); the effects were invariant between black and white girls, independent of cardiorespiratory endurance and body fatness, and consistent across a 1-yr period. CONCLUSION The positively worded nine-item version of the SMI-C can be used in cross-sectional, prospective cohort, and intervention studies that examine self-motivation as a putative moderator or mediator of physical activity among black and white adolescent girls.