Patterns of habitual activity across weekdays and weekend days in 9-11-year-old children

To characterize the pattern of activity in boys and girls across weekdays and weekend days.

Physical activity was recorded every 2 s by uniaxial accelerometry in 84 children, aged 9-11 years, for up to four weekdays and two weekend days. Activity bouts (>or= 4 s and >or= 5 min) greater than light (>or= LIGHT), moderate (>or= MOD) and vigorous (>or= VIG) intensity were recorded. The study took place in the South-West of England in 2007.

The mean duration of activity bouts decreased as intensity increased from 11.0+/-1.3 s for >or= LIGHT activity to 6.1+/-1.0 s for >or= VIG activity. The frequency, duration and intensity of bouts were greater in boys than girls, and the frequency and duration of bouts were greater on weekdays than weekend days. Girls accumulated more activity sporadically than boys, whereas boys accumulated more activity in >or= 5-min bouts.

Sex differences and weekday/weekend differences in activity were largely due to the intensity of the most frequent bouts of activity and frequency of the most intense bouts. Information regarding the pattern of children's habitual activity can be used to inform activity interventions and assess the aspects of the activity pattern that are related to health.