The Association Between Sex and Directly Observed Physical Activity in Preschool-Age Children

Abstract

Sex disparities in physical activity (PA) are evident in preschool-age children (2.9 – 5 years old). Preschool-age boys have been reported to participate in more PA during free play. However, it is unknown if this disparity is evident when participating in a structured PA intervention. PURPOSE: To examine the association between sex and directly observed PA levels in preschool-age children while participating in a PA intervention. METHODS: This study utilized data from the Short bouTs of Exercise for Preschoolers (STEP) study. STEP was a 6-month cluster randomized controlled study that examined the effects of short bouts of structured PA implemented within the classroom setting as part of designated gross motor playtime in ten preschool centers. STEP consisted of structured PA during the first 10 minutes of gross motor playtime followed by 20 minutes of free playtime. PA levels during the 10-minute intervention session were measured using a modified Observational System for Recording Physical Activity in Children-Preschool Version. PA intensity was classified as sedentary, light, or moderate-to-vigorous (MVPA). This secondary analysis focused on the baseline and 3-month data of participants randomized to the intervention group (preschool centers, n = 5; participants, n = 75; age = 3.9 ± 0.67 years). Spearman correlations were used to examine the association between sex and PA intensity during the intervention. Repeated measures ANOVAs were used to examine the effect of sex on PA intensity. RESULTS: Participants spent similar percent of intervals in MVPA at baseline (boys, 41.77±6.59; girls,38.27±5.16) and 3-months (boys, 46.61±7.59; girls, 43.89±7.55). There were no significant associations between sex and directly observed MVPA at baseline (r=-0.035, P=0.37) or 3-months (r=-0.039, P=0.81). Similarly, there were no significant effects of sex on any PA intensity (all P > 0.80) during the intervention. CONCLUSION: In this sample, sex was not associated with or impacted the number of intervals that preschool-age children spent in MVPA during the structured PA intervention. Future studies are needed to determine if these trends remain the same in a larger sample size. Funded by: Robert Wood Johnson Foundation, Active Living Research Grant 68509