Physical Activity Patterns and Correlates of 9-Month-Old Chinese Infants in the Macau Population.

Objectives Many obesity-related chronic diseases originate from unhealthy childhood habits. The aim of this study was to describe 9-month-old infants' physical activity levels and patterns and to examine the correlates. Understanding these factors is necessary for improving the effectiveness of physical activity intervention programs for infants. Methods In total, 143 infant-mother dyads from Macau, SAR China, participated in this study. Physical activity (PA) was assessed by using the Actigraph GT3X+ accelerometer and the demographic variables were collected by questionnaires. Results The most important findings were that: (1) infants had more screen time during weekdays (p = .044); (2) infants and mothers were least active at 8 a.m. (both weekdays and weekends) in the morning and most active at 7 p.m. (weekdays) and 8 p.m. (weekends) in the evening; (3) infants' PA levels significantly correlated with their mothers' PA intensities during the weekends (r = .192, p = .036), especially the mothers' lower intensities in the mornings and evenings; (4) maternal BMI predicted the PA levels of the 9-month-old infants' (R2  = .06, β = 29.188, p = .009). Conclusions for Practice Physical activity promotion programs for infants should be time-specific starting from early infancy. This study was one of the first to examine 9-month-old infants' PA levels, patterns and correlates. The results may be helpful in improving the effectiveness of future healthy lifestyle intervention programs for infants in Macau and in the region in general.