A comparison of low-intensity physical activity, growth, and sleep behavior in 6-month old infants.

This study examined low-intensity physical activity (PA), sleep behavior (24-hour accelerometry), and growth in 22 6-month old infants. Relationships were assessed using bivariate correlations. Infants accumulating less 'total' sleep spent more time in low-intensity PA (r = -.524, p = .012). Those with less 'nighttime' sleep had greater nap frequency (r = -.460, p = .031), nap duration (r =  -.529, p = .011) and weight-for-length z-scores (r = -.481, p = .024), but still accumulated less total sleep (r = .608, p = .003). These preliminary data highlight the importance of promoting healthy nighttime sleep behavior during infancy.