Associations Between Daily Step Counts And Physical Fitness In Preschool Children

Purposes: To investigate the relationships between daily step counts and physical fitness in preschool children and whether there is a threshold of steps per day to achieve the high health-related physical fitness level.Methods: Preschoolers' step counts were assessed by Acti Graph accelerometers consecutively for seven days.Physical fitness was assessed by a 20 meter shuttle run test(cardiorespiratory fitness),the handgrip and standing long jump tests(musculoskeletal fitness),and the 2 × 10 meter shuttle run test(speed/agility).A composite Z-score was created from the mean of the standardized values of all physical fitness tests and categorized into quartiles,the highest quartile of Z-score was defined as high physical fitness.Logistic and linear regressions were applied to estimate the associations between daily step counts and high physical fitness.Results: A total of 301 preschoolers(167 boys,mean age 58.10 ± 5.34 months;134 girls,mean age 57.40 ± 5.47 months)were included in the final analysis.Compared with the lowest tertile,boys and girls in the highest tertile of step counts achieved high physical fitness with odds ratio(OR)being 5.39(95% CI = 1.65–17.59)and 4.42(95% CI = 1.30–14.99),respectively,after adjusting for confounders.Meanwhile,a relationship was observed for each 1000 steps/day increment being associated with 43%(OR = 1.43,95% CI = 1.10-1.85)and 62%(OR = 1.62,95% CI=1.20–2.19)increment for high physical fitness in boys and girls,respectively.In addition,significant non-linear relationship was observed between daily steps and physical fitness in boys,which indicated that accumulated 8000 steps/day was associated with the highest ratio to achieve high physical fitness.Conclusions: Positive dose-response relationships between step counts and physical fitness were observed in preschool children,and the relationships were strongest for those who accumulated 8000 steps/day in boys.To confirm the findings in this study,well-designed and large-scale longitudinal studies are needed in the future.