This study was conducted to evaluate the relationship between objectively measured sedentary behavior (SB) and motor coordination (MC) in Portuguese children, accounting for physical activity (PA), accelerometer wear time, waist-to-height ratio, and mother's education level.
A cross-sectional school-based study was conducted on 213 children (110 girls and 103 boys) aged 9–10 in the north of Portugal during the spring of 2010. Accelerometers were used to obtain detailed objective information about daily PA and SB over five consecutive days. MC was measured with a body coordination test (Körperkoordination Test für Kinder). Waist and height were measured by standardized protocols and the waist-to-height ratio (WHtR) was calculated. A questionnaire was used to assess mothers' educational levels. Receiver-operating characteristic (ROC) and logistic regressions were used.
ROC analysis showed that sedentary time significantly discriminated between children with low MC and high MC, with a best trade off between sensitivity and specificity being achieved at ≥77.29% and ≥76.48% for girls and boys, respectively (P < 0.05 for both). In both genders, the low sedentary group had significantly higher odds of having good MC than the higher sedentary group, independent of PA, accelerometer wear time, WHtR, and mother's education level (P < 0.05 for both).
Our findings suggested that PA levels per se may not overcome the deleterious influence of high levels of SB on MC. Our data stress the importance of discouraging SB among children to improve MC. Am. J. Hum. Biol., 2012. © 2012 Wiley Periodicals, Inc.