Institutional Review Board approval was obtained prior to the start of any study procedures (Concordia University Wisconsin ID: 932380-3; 926512-1). Additionally, all protocols and procedures were approved by the research board at the school district level, as well as the principal at each school. In an effort to ensure we could include a maximum number of children on the playground, a passive consent protocol was followed. Consent forms were sent home to each student and parents and students were given the opportunity to opt out of the current study. In accordance with school district policy on passive consent protocols, personally identifying information was not collected on participants.
Participants
Participants included children at 13 urban elementary schools in the U.S. Across the 13 schools, accelerometer data were collected at 55 recess sessions, with 3,419 child-level observations (n = 1,696 boys; n = 1,723 girls). Observations of engagement in recess activities were collected at 61 recess sessions with 4,528 child-level observations (n = 2243 boys; n = 2285 girls). The number of children within each recess session ranged from 12 to 117 with an average of 62.16 (SD = 26.34) children per recess. All schools enrolled in this study served children in low-income areas, with publicly available data showing that 78.8% of the student population is economically disadvantaged (12-out-of-13 schools > 50% of economically disadvantaged students; range = 22.5% − 99.6%). Of the 13 schools, 10 were in the public-school system, with three of these 10 schools being language immersion schools. Twelve of the 13 schools were exclusively elementary schools (i.e., grades 1–5), and one school also served middle school students (i.e., grades 4–8). Enrollment at each school ranged from 253 students to 690 students, with an average of 436 students per school.
Measures
Physical activity. The Fitbit Flex™ is a wrist worn triaxial accelerometer that uses proprietary algorithms to estimate steps counts and time spent in various activity levels. The Fitbit Flex provides the most simplistic user display of all Fitbit products, with only LED lights to represent progress towards daily goals (the default setting is 10,000 steps; 2000 steps per dot shown). This was thought to be advantageous, as participants would not be able to directly monitor their step counts of physical activity levels during recess. The Fitbit Flex can by synched wirelessly to a smart phone or tablet, and provides information on steps counts and time spend in various activity levels (i.e., sedentary, light, moderate, vigorous). For the purposes of the current study, the research team created anonymous accounts for each device that could only be accessed by the research team. Each account was assigned to either a male or female user, with national averages for height and weight being used for user demographic information. Fitbits were placed on students in their classroom, or in the lunch room, approximately 30 minutes prior to the start of recess. Data assessors recorded the exact start and stop times of recess so that data could be extracted to match the time stamp. Data were housed by a third-party vendor (Fitabase LLC, San Diego, California) and processed using 60 second epochs within the noted time stamp, the most sensitive setting available for this device. In child-based studies, both waist-worn (24) and wrist worn (25) Fitbit devices (Fitbit One and Fitbit Charge, respectively) have been shown to have consistent levels of step counts with Actigraph accelerometers, yet may over-estimate absolute number of steps, as well as time spent in MVPA. Additional research in young adult populations has shown moderate validity between the wrist-worn Fitbit Flex and the wrist-worn Actigraph GT3X + in free-living conditions (26), yet the Fitbit flex showed higher levels of variability, and was more likely to under-estimated activity levels.
Recess quality. The Great Recess Framework – Observational Tool (GRF-OT) was used as a measure of recess quality in the current study. The GRF-OT represents four domains of recess that include safety and structure of the playground, adult supervision and engagement, student behaviors, and transitions to and from the recess space (23). In the current study data was collected on three of the four sub-scales (transitions were excluded, as they account for the times immediately before and after recess and the focus of the current study was PA during recess). Items are scored on a 4-point scale by a live observer who was present at recess (4 = highest quality; 1 = lowest quality). The safety and structure sub-scale examines the physical environment and access to equipment; the adult engagement and supervision sub-scale examines the number of adults present, their proximity to students, and whether or not they engage with students on the playground; and the student behaviors sub-scales examines student engagement, initiation of play, conflict, and conflict resolution. Each item and its associated scoring procedure can be found in Massey et al. 2018 (20). A complete scoring manual with detailed instructions is available at www.greatrecessframework.org. Data in the current study suggest acceptable levels of internal consistent for the safety and structure sub-scale (α = .806), adult engagement and supervision sub-scale (α = .736), and student behavior sub-scale (α = .788). Previous research has shown support for the inter-rater reliability and factorial validity of the GRF-OT (23).
Engagement in recess activities. The different types of activities children engaged in during recess were measured using the Observations of Playground Play (OPP) (22). The OPP allows observes to code engagement in 32 common recess activities across eight different play domains. Observers are also able to write in observed behaviors within each of the eight domains to ensure all recess activities are captured. Previous research has been reported on the reliability of this assessment tool (22).
Basic psychological needs satisfaction (BPNS). A sub-sample of fourth and fifth grade students (n = 820) completed a modified version of the basic psychological need satisfaction scale (27). The original 21-item questionnaire designed to assess individual perceptions of autonomy (7 items), competence (6 items), and relatedness (8 items) need satisfaction at work was modified to specifically examine children’s need satisfaction during recess and reduced to two-items per scale to ensure comprehension for a younger population. Additionally, two items related to physical and emotional safety at recess were added to the scale. All responses corresponded to a 5-point Likert scale (5 = high need satisfaction) on items such as “I feel like I can say my ideas about what I want to do at recess” (autonomy), “Kids tell me I am good at things I do at recess” (competence), “I really like the kids I play with at recess” (relatedness), and “I am safe when I am playing at recess” (safety).
Procedures
With the exception of one school that conducted concurrent indoor and outdoor recess periods, all recess data collection periods were conducted outside. Data collection took place between February and May in a large city in the Midwestern region of the United States. Recess periods ranged from 12 minutes to 40 minutes in length (M = 21.12 minutes; SD = 5.83 minutes) and primarily included traditional lunch recess periods. Schools maintained variable schedules, with some schools sending groups of students outside all at once, while others rotated the sessions with different children and different supervisors (e.g., only first through third graders at recess one, followed by only fourth and fifth graders at recess two).
Outcome assessors arrived to the school approximately 60 minutes before the scheduled recess session to ensure students were properly fitted with activity monitoring devices. Each data collection period contained four study team members. Two members of the team were assigned to ensure compliance in terms of properly wearing the activity monitoring devices. The other two team members collected observational data throughout the entire recess session. Data using the GRF-OT were collected by the PI or a trained graduate student. In all cases, the recess environment was completely visible to the outcome assessor, and the outcome assessor moved throughout the playground in a discreet manner in an effort to observe patterns of interaction and behavior. Final scoring of each item was completed immediately after the recess session and took into account the aggregate patterns of behavior throughout the duration of the recess session. Data using the OPP were collected at five-minute intervals across each recess period. OPP data were then averaged to create a composite level of student engagement in different activities for each recess session.
Data Analysis
Prior to data analysis, Fitbit Flex data were screened and devices registering 0 step counts in the recess time recording were eliminated from the dataset. Time recordings of the beginning and ending of each recess session were kept to allow for specificity in data extraction when examining recess-based physical activity. Furthermore, Fitbit numbers were logged and tracked for each recess session to ensure which devices were in use for each session, and which devices were returned at the end of each recess session. Given the varying times and number of students across recess sessions, we converted physical activity data to the percent of time spent in MVPA or light physical activity (LPA) during recess and used these percentages as the dependent variable in primary analyses.
Primary analyses were conducted using Hierarchical Linear Modeling (HLM) with children nested within recess sessions. Intercepts freely varied across recess sessions, while all primary predictors were entered as fixed effects. An unconditional nested model was first tested to examine possible recess-level effects for all dependent variables (i.e., physical activity levels). Next, models were fitted in which recess quality score indicators (i.e., adult engagement and supervision, student behaviors, safety and structure) were entered as predictors of physical activity levels while controlling for school as a fixed effect. Moderation was also tested by examining the interaction between gender (a level one predictor) and recess quality indicators (a level two predictor) on levels of physical activity during recess. Significant interactions were probed to examine the simple slopes and intercepts as a function of gender using the formula depicted below and as described by Preacher and colleagues (28), where ý00 represents the intercept, ý01, ý10 and ý11 are the regression coefficients, x represents the focal predictor, and w represents the moderator variable.
yij = ý00 + ý10x1 + ý01w1 + ý11w1x1
Finally, trends across recess quality were examined relative to high- and low-quality recess sessions (i.e., one SD above and one SD below the sample mean). In general, high-quality recess sessions were characterized by safe physical environments (e.g., lack of hazardous materials), a broad range of equipment and activities to engage in play, prosocial student behaviors (e.g., initiating games, positive communication, lack of physical violence) and present and engaged adults. In contrast, low-quality recess sessions were often characterized as unsafe environments (e.g., glass and hazardous debris), limited or no equipment to use for game play, verbal and physical conflicts, and disengaged adults. Aggregate profiles of recess sessions in the upper and lower quartile for GRF-OT scores were created to examine differential patterns in the games and activities in which children participate in, and the psychological need satisfaction of children during recess.