Move or sit: Preschoolers' in-kindergarten physical activity and its association with fundamental motor skills using...

This observational study examined physical activity (PA) across three kindergarten contexts and its association with fundamental motor skills (FMS), with a proprietary AI-assisted video/action-analysis tool used as a supplementary assessment aid. Fifty-seven children (61.11 ± 12.73 months; range 45-81 months) from one kindergarten in Chengdu, China, were observed during morning exercise, organized physical education (PE), and free play using the Observational System for Recording Physical Activity in Children-Preschool Version (OSRAC-P); FMS were assessed with the standardized Fundamental Movement Skills Development Test for Children Aged 3-10 Years. The AI component was the proprietary "Xiaoneng Classmate" action-analysis platform developed by Chengdu Tixiaoneng Education Technology Co., Ltd.; manufacturer materials document AI-assisted action/video analysis and digital testing/data functions but do not disclose a public model architecture or study-specific validation metrics. Mean activity level was highest during morning exercise (3.29 ± 0.09), followed by free play (2.94 ± 0.40), and lowest during organized PE (2.46 ± 0.26). Organized PE had the highest sedentary frequency (46.58% ± 12.69%), whereas free play had the highest MVPA frequency (33.92% ± 13.03%). To address multicollinearity in the original high-dimensional regression, parsimonious individual-level models adjusted for age, sex, and BMI and included MVPA during organized PE and free play. Organized-PE MVPA was positively associated with locomotor skill score (B = 0.471 per percentage point, HC3 SE = 0.141, β = 0.407, 95% CI [0.187, 0.754], p = .002) and showed a weaker association with total FMS (B = 0.484, HC3 SE = 0.235, β = 0.234, 95% CI [0.011, 0.957], p = .045); no PA predictor was significant for object-control or stability scores. Morning-exercise MVPA was not entered in the individual-level regression because it had no within-class variability. These findings are context-specific associations and do not establish causal direction.