An Ecological Momentary Assessment (EMA) Study on Youth Physical and Sedentary Activities: Gender and Ethnic Differences

Introduction. Most youth do not engage in the amount of physical activity (PA) recommended by the World Health Organization and they tend to exceed the amount of sedentary activity (SA) recommended. This puts adolescents at risk for becoming obese, which is associated with numerous health problems. Earlier studies have shown that adolescent girls engage in less PA than boys, placing them at higher risk for poor health outcomes. Although results have been mixed, there may also be ethnic disparities in obesity and PA in youth. The purpose of this presentation is to investigate the gender and ethnic differences in PA and SA during early adolescence. We also explore how location and social context may impact activities.

 Methods. Participants were 403 8th grade youth (48% male, 38% Hispanic) from 7 communities in Oregon. Ecological Momentary Assessment (EMA) captured information on youth’s activities, social affiliations, and location in real time. Youth were prompted on an iPod Touch to complete a short EMA on 18 occasions from Thursday to Sunday at random times during non-school hours. On average, participants answered 79.6% of the prompted surveys, for a total of 5777 answered surveys. Hierarchical linear models with survey occasion nested into persons tested gender and ethnic differences in PA and SA.

 Results. Youth were engaged in PA on 15% of the occasions and in screen-based SA on 30% of the occasions. Boys were more likely to engage in PA than girls; log odds ratio (OR) = 1.97 (95% CI 1.48, 2.67), t = 4.33, p < .001. There were no differences between Hispanic and non-Hispanic youth in PA. Hispanic youth were less likely to engage in SA than non-Hispanic youth; log odds ratio = .69 (95% CI 0.51, 0.95), t = -2.30, p = .022. Gender by ethnicity interactions were not significant. PA occurred more when youth were with their peers; log odds ratio = 4.24 (95% CI 2.73, 6.56), t = 6.47, p < .001. SA occurred more when peers were not present; log odds ratio = .66 (95% CI 0.48, 0.91), t = -2.57, p = .011. These associations did not differ by gender or ethnicity. PA occurred at home 35% of the time and in unorganized community places 31% of the time, and less so in organized school, church, or recreation locations (11% of the time). SA activities mainly occurred at home (85% of the time).

 Conclusion. Understanding the contexts of youth physical and sedentary activities will help identify important populations to target and ways to promote PA to prevent obesity and affiliated health problems. We found that girls engaged in PA less than boys and that Hispanics engaged in fewer screen-based SA than non-Hispanics. PA appears to be a social activity for all youth. EMA methodology is ideal for understanding the ways in which environments impact health behaviors.