Date of Award

May 2023

Degree Type


Degree Name

Doctor of Philosophy



First Advisor

Ann M Swartz

Committee Members

Scott J Strath, Chi C Cho, Christy A Greenleaf, Young I Cho


Adolescent, Classroom, Elementary, Youth


Children and adolescents spend the majority of their day engaged in sedentary behaviors (SB), while also not meeting physical activity (PA) recommendations. The failure to develop and maintain health enhancing behaviors from a young age may impact an individual throughout their life. With children and adolescents spending a large proportion of their waking hours in a school setting, the educational environment presents an opportunity in which children and adolescents’ PA and SB can be positively influenced. Therefore, the purpose of this dissertation was to explore how children and adolescent’s school time PA and SB are associated with the educational setting, and how these behaviors change over the course of the school year and in response to non-traditional classroom settings. To address this purpose, three individual studies were completed. Study 1: Comparison of measures of elementary student’s classroom postural behaviors using direct observation and accelerometry in a school setting. The results of our research are only as good as the measures used, therefore to begin this series of studies two commonly used objective methods to assess children’s PA and SB were compared. Specifically, the inclinometer function of a hip-worn Actigraph GT3X+ accelerometer (ACC) and direct-observation (DO) were evaluated in their measurement of child and adolescent posture within a classroom environment that included stand-biased and traditional seated desks. Our results suggest that the measurement of both sitting and standing while in either a stand-biased or traditional seated desk were significantly different between DO and ACC, with DO consistently recording a higher proportion of time spent sitting, and a lower proportion of time standing regardless of desk assignment. The difference between DO and ACC measures of sitting (-18.9%; p=0.041) were significantly smaller when students used a stand-biased compared to a traditional seated desk. There was no significant difference between DO and ACC measures of standing between desk types, and lower limb fidgeting was found to have no main or interaction effect between desk type and differences of postural measures. It is important to remain cognizant of the methodologies used to assess youth behaviors, and the influence these measurement techniques can have on intervention outcomes involving environmental and other behavioral modifications. Study 2: An exploration into the variation of children’s in-school physical activity across the school year. Study two explored the variation in children and adolescents PA behaviors during active periods of the school day across the school year. Participating students completed a survey on five separate occasions throughout the school year, assessing activity levels during active transportation to and from school, at recess, and in physical education class. Our results suggest that overall, the weekly minutes that children and adolescents spent engaging in moderate- to vigorous-intensity PA (MVPA) remained relatively stable during recess (Avg: 42.2±12.2 minutes/week) and physical education class (Avg: 17.7±5.6 minutes/week) throughout the year. Statistically significant differences were found in the estimated weekly minutes of MVPA accumulated during active transportation to- and from-school, with the greatest accumulation occurring in September (To-School: 15.3±5.7 minutes/week; From-School: 32.0±10.5 minutes/week), and the lowest accumulation of MVPA to-school and from-school occurring in December (13.9±6.5 minutes/week; p=0.01) and March (28.5±11.9 minutes/week; p<0.001), respectively. During active transportation to-school, weekly MVPA was highest in September (Fall; 15.3±5.7 minutes/week), and lowest in December (Winter; 13.9±6.5 minutes/week; p=0.01), while significant differences in active transportation from-school occurred between September (Fall; 32.0±10.5 minutes/week), December (Winter; 29.6±11.6 minutes/week; p=0.003), March (Spring; 28.5±11.9 minutes/week; p<0.001), and April (Spring; 29.2±12.0 minutes/week; p<0.001). Opportunities for PA throughout the school day may have been insufficient to aid youth in meeting recommendations, however the weekly opportunities which students are provided to engage in MVPA do not vary meaningfully throughout the year. To address this, school administrators may consider increasing the frequency and length of time which students are provided to engage in PA throughout the school day, such as during recess and physical education class, or by seeking to increase participation during periods of the school day where students are less consistently active throughout the school year, including during active transportation to- and from-school. Study 3: Comparison of children’s physical activity and sedentary behaviors between a nature-based and traditional educational setting. The third and final study of this dissertation aimed to compare within-child differences in PA and SB of a sample of children attending a single Pre-Kindergarten (Pre-K) educational program which alternated school days between a traditional and nature-based school setting. Overall, the results from this study suggest that children spent a significantly greater proportion of school time engaging in MVPA (+2.4±3.4%; p=0.002) while in a nature-based compared to a traditional Pre-K setting. Moreover, differences in MVPA between a nature-based and traditional program setting were most pronounced during the winter (~6 min/day), particularly while engaging in unstructured free play (~5 min/day). While the winter season has been shown to be a time when youth PA levels are at their lowest, the PA levels of children while in a nature-based setting remained constant from winter to spring. Therefore, modifying educational practices to increase opportunities for structured and unstructured activities outdoors, particularly during periods of the year when children are least active, may have the potential to positively influence children’s in-school PA and SB. Overall Conclusion. Together, these dissertation findings contribute toward a better understanding of the potential that the school setting has to provide meaningful and consistent opportunities for youth to engage in more active behaviors throughout the school day. The methodological approach of Study 1 highlights the differences in the measurement and interpretation of youth activity behaviors encountered when the methods of assessment vary, particularly as schools may seek to modify educational environments and promote more active behaviors. Study 2 provided insight into times of the school day and periods throughout the school year in which opportunities for children and adolescents to engage in PA can be enhanced, and Study 3 reinforces the relationship between time outside and children’s PA levels, providing one avenue for traditional school programs to incorporate more activity into the school day. Overall, the results of these studies provide school administrators and decision makers with important information surrounding school-related factors which are associated with children and adolescents PA and SB, and inform improvements in opportunities for the accumulation of school time PA. Ultimately, this dissertation contributes towards a body of research seeking to increase the quantity and quality of activity behaviors youth engage in, and to aid in the development of the healthy habits that children and adolescents practice throughout their lifespan.