Sex Differences In The Efficacy Of The Short Bouts Of Exercise For Preschoolers (STEP) Intervention

INTRODUCTION: Physical activity (PA) has been shown to have both short and long-term benefits for preschool-aged children (3 – 5 years of age). However, most preschoolers do not meet PA guidelines. Similar to older children and adolescents, female preschool-age children tend to participate in less moderate-to-vigorous PA (MVPA) compared to their male counterparts. However, it is unclear if this sex difference persists during PA interventions. PURPOSE: The purpose of this study was to examine sex differences in the effectiveness of a 6-month intervention designed to improve the PA levels of preschool-age children using short bouts of PA. METHODS: This secondary analysis used data [baseline and 3-month (midpoint)] from the Short bouTs of Exercise for Preschoolers (STEP) study, which examined the efficacy of a short-bout PA intervention in preschoolers. The intervention was delivered 10 minutes/day, four days/week for six months. PA was assessed with accelerometers during the preschool day. An ANOVA was used to examine biological sex differences in changes in PA intensity (sedentary, light, moderate, vigorous, MVPA) from baseline to midpoint. RESULTS: n = 32 males and n = 40 females had complete data at both baseline and midpoint. There were no significant differences (p > 0.05) between males and females with regard to age or PA levels. There was no significant interaction between sex and measurement timepoint for any of the PA intensities. There was no significant interaction between biological sex and measurement timepoint. CONCLUSION: There was no significant difference in intervention effectiveness between boys and girls for any other PA intensities. The STEP intervention was successful in not widening the pre-existing PA gap between preschool-aged males and females. However, it also did not close this gap. While both boys and girls are not meeting PA recommendations, interventions are needed to specifically target females.