Excessive screen time among adolescents increases risk for overweight and obesity. Having electronic devices in the adolescents bedroom is associated with more screen time. The present study expanded on previous studies by also examining portable personal electronic devices and social media membership as correlates of screen time use and total sedentary time in the school year and summer among diverse low-income adolescents. Adolescents aged 10-17 years were recruited from lower-income areas; n=150 (34 African Americans, 23 American Indians, 16 Asian/Pacific Islanders, 39 Latinos, and 38 White/non-Hispanics) completed surveys and wore accelerometers in both the school year and summer. Total sedentary time was computed from accelerometers. Recreational screen time was assessed with a 3-item validated scale. Adolescents reported the presence of 6 electronic devices in their bedrooms, ownership of 4 portable devices, and social media membership. General linear modeling was conducted for both time periods, with demographic covariates and interactions with sex and race/ethnicity. More electronic devices in bedrooms were related to more screen time during the school year and summer, and to more total sedentary time in summer. Personal electronics were related only to more screen time in the school year. Social media membership was related to more total sedentary time in summer, but only among African Americans, American Indians, and non-Hispanic Whites. Electronic devices in bedrooms was confirmed as a risk factor for sedentary behavior among low-income adolescents of color. Social media membership and use should be further studied with diverse adolescents.

2015 Copyright © SHAPE America Purpose: The study aims were to determine: (a) how class structure varies by dance type, (b) how moderate-to-vigorous physical activity (MVPA) and sedentary behavior vary by dance class segments, and (c) how class structure relates to total MVPA in dance classes. Method: Participants were 291 boys and girls ages 5 to 18 years old enrolled in 58 dance classes at 21 dance studios in Southern California. MVPA and sedentary behavior were assessed with accelerometry, with data aggregated to 15-s epochs. Percent and minutes of MVPA and sedentary behavior during dance class segments and percent of class time and minutes spent in each segment were calculated using Freedson age-specific cut points. Differences in MVPA (Freedson 3 Metabolic Equivalents of Tasks age-specific cut points) and sedentary behavior ( < 100 counts/min) were examined using mixed-effects linear regression. Results: The length of each class segment was fairly consistent across dance types, with the exception that in ballet, more time was spent in technique as compared with private jazz/hip-hop classes and Latin-flamenco and less time was spent in routine/practice as compared with Latin-salsa/ballet folklorico. Segment type accounted for 17% of the variance in the proportion of the segment spent in MVPA. The proportion of the segment in MVPA was higher for routine/practice (44.2%) than for technique (34.7%). The proportion of the segment in sedentary behavior was lowest for routine/practice (22.8%). Conclusion: The structure of dance lessons can impact youths' physical activity. Working with instructors to increase time in routine/practice during dance classes could contribute to physical activity promotion in youth.

Brief structured physical activity in the classroom is effective for increasing student physical activity. The present study investigated the association between implementation-related contextual factors and intervention implementation after adoption of a structured classroom physical activity intervention. Six elementary-school districts adopted structured classroom physical activity programs in 2013-2014. Implementation contextual factors and intervention implementation (structured physical activity provided in past week or month, yes/no) were assessed using surveys of 337 classroom teachers from 24 schools. Mixed-effects models accounted for the nested design. Availability of resources (yes/no, ORs = 1.91-2.93) and implementation climate z-scores (ORs = 1.36-1.47) were consistently associated with implementation. Teacher-perceived classroom behavior benefits (OR = 1.29) but not student enjoyment or health benefits, and time (OR = 2.32) and academic (OR = 1.63) barriers but not student cooperation barriers were associated with implementation (all z-scores). Four implementation contextual factor composites had an additive association with implementation (OR = 1.64 for each additional favorable composite). Training and technical assistance alone may not support a large proportion of teachers to implement structured classroom physical activity. In addition to lack of time and interference with academic lessons, school climate related to whether administrators and other teachers were supportive of the intervention were key factors explaining whether teachers implemented the intervention. Evidence-based implementation strategies are needed for effectively communicating the benefits of classroom physical activity on student behavior and improving teacher and administrator climate/attitudes around classroom physical activity.