Associations of Monitor-Independent Movement Summary and Health-Related Fitness With Gross Motor Skills in Young Children

The purpose of this study was to determine the associations device-based assessments physical activity (PA) and health-related fitness (HRF) with gross motor skills (GMS) in preschool-aged children. Participants were 3- 5-year-old children ( N = 316; 49.6% female) who participated 2012 National Youth Fitness Survey. GMS assessed using quotient calculated from Test for Gross Motor Development—Second Edition. PA wrist-worn ActiGraph GT3X accelerometers raw triaxial acceleration data summarized monitor-independent movement summary units (MIMS). Analyzed metrics included average MIMS per day peak 30-min MIMS. HRF assessment consisted a plank score sum skinfold assessment. Weighted hierarchical regressions tested between PA, HRF, variables secondary weighted mediation analysis that examined whether mediated association GMS. Peak significantly correlated b 0.17, p .005). Plank scores had strongest correlation 0.23, .004), analyses revealed partially (indirect effect 0.03, .01, 23.1% mediation). associated preschool children, an by core muscular endurance.