Marsha Dowda

Motivation and Behavioral Regulation of Physical Activity in Middle School Students.

PURPOSEnThis study aimed to examine whether intrinsic motivation and behavioral self-regulation are related to physical activity during middle school.nnnMETHODnStructural equation modeling was applied in cross-sectional and longitudinal tests of self-determination theory.nnnRESULTSnConsistent with theory, hypothesized relations among variables were supported. Integrated regulation and intrinsic motivation were most strongly correlated with moderate-to-vigorous physical activity measured by an accelerometer. Results were independent of a measure of biological maturity. Construct validity and equivalence of measures were confirmed longitudinally between the sixth and seventh grades and between boys and girls, non-Hispanic Black and White children and overweight and normal-weight students.nnnCONCLUSIONSnMeasures of autonomous motivation (identified, integrated, and intrinsic) were more strongly related to physical activity in the seventh grade than measures of controlled motivation (external and introjected), implying that physical activity became more intrinsically motivating for some girls and boys as they moved through middle school. Nonetheless, change in introjected regulation was related to change in physical activity in the seventh grade, suggesting that internalized social pressures, which can be detrimental to sustained activity and well-being, also became motivating. These results encourage longer prospective studies during childhood and adolescence to clarify how controlled and autonomous motivations for physical activity develop and whether they respond to interventions designed to increase physical activity.

Sedentary Behaviors in Fifth-Grade Boys and Girls: Where, With Whom, and Why?

BACKGROUNDnAn understanding of the context surrounding screen- and non-screen-based sedentary behavior would facilitate efforts to reduce childrens overall sedentary behavior. This study examined the prevalence of specific types of sedentary behavior in children, the social and physical contexts surrounding these behaviors, and differences by gender.nnnMETHODSnParticipants included 686 fifth graders participating in the Transitions and Activity Changes in Kids Study (TRACK). The Physical Activity Choices instrument measured child participation in seven sedentary behaviors, the social (i.e., with whom) and physical (i.e., where) contexts, and perceptions (i.e., why) of those behaviors. Analysis included mixed-model regression adjusted for race/ethnicity, BMI, and socioeconomic status.nnnRESULTSnChildren participated in both screen- and non-screen-based sedentary behaviors at very high frequencies. The most popular activities included watching television or videos, listening to music, playing video games (boys only), and talking on the phone or texting (girls only). Children engaged in sedentary behaviors most often at home, at school, or in their neighborhood. In general, the patterns of social context for the behaviors were similar for boys and girls, with the exception of video game playing. Girls perceived listening to music and talking on the phone or texting to be more fun than boys; children did not differ in their other perceptions (i.e., how much choice or how important) of the behaviors.nnnCONCLUSIONSnMulti-level interventions that target reducing sedentary behavior in the home, neighborhood, and school context may be most effective; however, the approach needed will likely differ by gender.

Construct Validity of Selected Measures of Physical Activity Beliefs and Motives in Fifth and Sixth Grade Boys and Girls

OBJECTIVEnScales used to measure selected social-cognitive beliefs and motives for physical activity were tested among boys and girls.nnnMETHODSnCovariance modeling was applied to responses obtained from large multi-ethnic samples of students in the fifth and sixth grades.nnnRESULTSnTheoretically and statistically sound models were developed, supporting the factorial validity of the scales in all groups. Multi-group longitudinal invariance was confirmed between boys and girls, overweight and normal weight students, and non-Hispanic black and white children. The construct validity of the scales was supported by hypothesized convergent and discriminant relationships within a measurement model that included correlations with physical activity (MET • min/day) measured by an accelerometer.nnnCONCLUSIONSnScores from the scales provide valid assessments of selected beliefs and motives that are putative mediators of change in physical activity among boys and girls, as they begin the understudied transition from the fifth grade into middle school, when physical activity naturally declines.

After-school setting, physical activity, and sedentary behavior in 5th grade boys and girls.

After-school hours are considered critical for childrens physical activity (PA) and sedentary behaviors (SB); however, whether the after-school setting influences childrens activity patterns is unknown. This study examined the influence of after-school setting (i.e., parent report of the childs usual after-school setting) on 5th grade childrens PA and SB, and differences by race/ethnicity. Boys whose parents reported they usually attended an after-school program had higher PA than boys who usually went home after school. A significant interaction between race/ethnicity and after-school setting showed that minority girls whose parents reported they usually attended an after-school program had higher PA and engaged in less SB compared with those who usually went home, whereas the activity patterns of white girls did not differ by after-school setting. Childrens usual after-school setting affects their activity patterns; after-school programs may potentially increase PA in boys and minority girls.

Associations Between Home Environment and After-School Physical Activity and Sedentary Time Among 6th Grade Children.

This study examined associations of various elements of the home environment with after-school physical activity and sedentary time in 671 6th-grade children (Mage = 11.49 ± 0.5 years). Childrens after-school total physical activity, moderate-to-vigorous physical activity, and sedentary time were measured by accelerometry. Parents completed surveys assessing elements of the home social and physical environment. Mixed-model regression analyses were used to examine the associations between each element of the home environment and childrens after-school physical activity and sedentary time. Availability of home physical activity resources was associated positively with after-school total physical activity and negatively with after-school sedentary time in boys. Parental support was associated positively with after-school total physical activity and MVPA and negatively with after-school sedentary time in girls. The home physical environment was associated with boys after-school physical activity and sedentary time, whereas the home social environment was associated with girls after-school physical activity and sedentary time.

The Modifying Effects of Race/Ethnicity and Socioeconomic Status on the Change in Physical Activity From Elementary to Middle School

PURPOSEnYouth physical activity (PA) levels differ by race/ethnicity and socioeconomic status (SES). It is well established that various multilevel factors may influence changes in PA. The present study examined whether the association between the change in individual, interpersonal, and environmental factors and the change in PA is modified by race/ethnicity or SES.nnnMETHODSnThis study followed 643 youths and their parents from suburban and rural South Carolina participating in the Transitions and Activity Changes in Kids (TRACK) Study in 2008-2009 and 2010-2011. We assessed total PA in youth using accelerometry and categorized youth and parent survey data into blocks based on the socioecological model. Multivariate regression growth curve models evaluated whether the association between change in independent variables and change in PA was modified by race/ethnicity or SES.nnnRESULTSnPA declined from fifth to seventh grade among all racial/ethnic and SES groups. Associations between the range of variables and change in PA were modified by race/ethnicity but not SES. Blacks did not share any common predictors of change in PA with whites or Hispanics. However, child-reported number of active friends was associated with total PA, and enjoyment of PA was associated with change in PA among both whites and Hispanics. Significant interactions by time varied by racial/ethnic group.nnnCONCLUSIONSnThe factors that influence changes in youth PA vary by race/ethnicity but not SES. These findings reinforce the complex nature of addressing PA behavior in diverse samples and further support the need for culturally appropriate interventions to promote PA in youth.

Associations Between Maternal Support and Physical Activity Among 5th Grade Students

Background A large body of research has established an association between parental support for children’s physical activity (PA) and children’s PA. However, there has been little attention to the relative influences of parent and child perceptions of that parental support. Purpose To examine agreement among parent and child perceptions of parent support for PA and whether these perceptions are associated with objectively-measured moderate-to-vigorous physical activity (MVPA) among those children. Methods Cross-sectional associations between PA of children measured via accelerometers and child-reported and mother-reported perceptions of parental support for children’s PA were assessed via mixed-model regression analyses in a cohort of 693 5th graders. Results Children’s perceptions of parental support for PA were consistent with those of their mothers. Nonetheless, in models that included both children’s and mothers’ perceptions of parental support for PA, mothers’ perceptions, but not children’s perceptions, were significantly associated with children’s PA. Associations were consistent for Total MVPA, After School MVPA, and Evening MVPA, with stronger associations among males than among females. Conclusion Maternal support may influence children’s PA. Studies which consider only children’s accounts of parental support may overlook important mechanisms.

Naturally-occurring changes in social-cognitive factors modify change in physical activity during early adolescence

Purpose To determine whether naturally-occurring changes in children’s motives and beliefs are associated with the steep decline in physical activity observed from childhood to early adolescence. Methods Latent growth modeling was applied in longitudinal tests of social-cognitive influences, and their interactions, on physical activity in a large cohort of boys and girls evaluated annually between 5th and 7th grades. Results Measurement equivalence of motives and beliefs was confirmed between boys and girls. After adjustment for gender and maturity differences, physical activity declined less in children who reported the least decreases in self-efficacy for overcoming barriers to activity and perceived parental support. Physical activity also declined less in students who persistently felt they had more parental and friend support for activity compared to those who reported the largest decrease in support from friends. After further adjustment for race, the decline in physical activity was less in those who had the largest decrease in perceived barriers and maintained a favorable perception of their neighborhood environment. Changes in enjoyment and social motives were unrelated to change in physical activity. Conclusion Using an objective measure of physical activity, we confirm that naturally-occurring changes in children’s beliefs about barriers to physical activity and their ability to overcome them, as well as perceptions of their neighborhood environment and social support, are concurrent with age-related declines in children’s physical activity. The longitudinal findings confirm these putative social-cognitive mediators as plausible, interacting targets of interventions designed to mitigate the marked decline in physical activity that occurs during the transition between elementary and middle schools.

Changes in Physical Activity in the School, Afterschool, and Evening Periods During the Transition From Elementary to Middle School

BACKGROUNDnWe examined longitudinal changes in childrens physical activity during the school day, afterschool, and evening across fifth, sixth, and seventh grades.nnnMETHODSnThe analytical sample included children who had valid accelerometer data in fifth grade and at least one other time-point, and provided complete sociodemographic information (Nu2009=u2009768, 751, and 612 for the 3 time-periods studied). Accelerometer-derived total physical activity (TPA) and moderate-to-vigorous physical activity (MVPA) were expressed in minutes per hour for the school day (∼7:45u2009am to 3:30u2009pm), afterschool (∼2:25 to 6:00u2009pm), and evening (6:00 to 10:00u2009pm) periods. We used growth curve analyses to examine changes in TPA and MVPA.nnnRESULTSnSchool day TPA and MVPA declined significantly; we observed a greater decrease from fifth to sixth grades than from sixth to seventh grades. Afterschool TPA declined significantly, but MVPA increased significantly among girls and remained stable for boys. Evening TPA decreased significantly and MVPA declined significantly in girls and remained stable among boys.nnnCONCLUSIONSnTo inform the development of effective intervention strategies, research should focus on examining factors associated with the decline in physical activity during the transition from elementary to middle school, particularly during the hours when children are in school.

Classes of Physical Activity and Sedentary Behavior in 5th Grade Children.

OBJECTIVESnWe identified classes of physical activity (PA) and sedentary behaviors (SB) in 5th grade children, associated factors, and trajectories of change into 7th grade.nnnMETHODSnThis study included N = 495 children (221 boys, 274 girls) who participated in the Transitions and Activity Changes in Kids (TRACK) Study. PA was assessed objectively as well as by self-report. Children, parents, and school administrators completed surveys to assess related factors. Latent class analysis, growth modeling, and adjusted multinomial logistic regression procedures were used to classify children based on self-reported PA and SB and examine associated factors.nnnRESULTSnThree classes of behavior were identified: Class 1: Low PA/Low SB; Class 2: Moderate PA/ High SB; and Class 3: High PA/High SB (boys) or Class 3: High PA (girls). Class 3 children had higher levels of self-efficacy (boys), and enjoyment, parental support, and physical activity equipment at home (girls). Class 2 boys and Class 3 girls did not experience decline in PA (accelerometer) over time.nnnCONCLUSIONSnSelf-efficacy (boys) and home environment (girls) may play a role in shaping patterns of PA in children. Findings may help to inform future interventions to encourage children to meet national PA guidelines.