Step to It: Exploring Longitudinal Associations Between Physical Activity and Cognition in Children.

Background: Identifying the relationships among physical activity (PA), cognition, and academic performance in children is important for targeted public health and education initiatives. However, most of the research has been cross-sectional in nature, and we have a limited understanding of how these associations change over time. Therefore, the aim of this study was to utilize longitudinal data to explore relationships among PA, cognition, and academic performance in elementary school children.

Methods: Data were sourced from 675 New Zealand children aged 5-11 years. Weekday home, weekday school, and weekend PA was measured by pedometer step readings, cognition by 4 measures from the Central Nervous System Vital Signs assessment, and academic performance from the New Zealand Ministry of Education Assessment Tools for Teaching and Learning reading and math scores. Measures were taken at baseline and 2- and 6-month intervals. Data were analyzed for 632 students identified with data for at least half of the 27 variables. A generalized linear mixed model was used to investigate changes in PA, cognition, and academic performance over those 3 time periods while adjusting for gender, school, age, and socioeconomic status.

Results: No significant relationships were identified between PA and 3 of the cognitive domains. However, significant, positive relationships were observed between PA change at 2 months and (1) composite memory change at 6 months, (2) math proficiency change at 2 months, and (3) math proficiency change at 6 months. Regression coefficients suggest that a child who doubles step count-a 100% increase in PA-is associated with a 3.7% improvement in math proficiency after 2 months and 2.6% and 4.7% in math proficiency and composite memory (respectively) after 6 months.

Conclusions: This 6-month longitudinal analysis identified that an increase in PA led to small but significant improvements in composite memory and math proficiency. This supports the theory that increase in PA leads to cognitive benefits. The small associations suggest that substantial improvements in PA would be required to generate meaningful improvements in cognition and academic achievement. However, timeframes longer than 6 months are recommended to identify long-term changes.