The Relationship with Meeting Physical Activity Guidelines in Preschool-Aged Children: A Systematic Review.

: Physical activity (PA) during preschool is vital for supporting physiological development, enhancing cognitive abilities and fostering socio-emotional growth. However, consistent disparities in meeting PA guidelines have been observed. This systematic review aims to identify studies that compared preschoolers' PA, as measured by technological devices, with recommended PA guidelines. Specifically, it examines (i) factors associated with meeting PA guidelines and (ii) the outcomes observed when children meet these guidelines. : The search strategy was designed based on the PICOS framework. Then, a systematic review was conducted using four databases to identify studies that included children from 0 to 6 years old participating in PA sessions recorded through technological devices. PA is compared with guidelines, and correlations were reported. : Of the 52 studies reviewed, most found that meeting PA guidelines in preschool-aged children was linked to favourable outcomes across multiple domains. Children who met the guidelines tended to show better motor competence, emotional regulation and cognitive skills, particularly in areas like working memory and social understanding. However, the relationship with body composition and body mass index was inconsistent, suggesting that the benefits of PA in early childhood extend beyond weight-related measures. : Meeting PA guidelines in early childhood is strongly associated with cognitive development, emotional regulation, motor skills and social behaviours. However, adherence varies significantly due to a complex mix of individual, familial, socioeconomic and environmental factors.