Objectively measured habitual physical activity in 1997/1998 vs 2003/2004 in Danish children: the European Youth Heart Study.

Based on two cross-sectional studies conducted in 8-10-year-old third-grade children living in the municipality of Odense, potential differences were examined in the level of habitual physical activity (HPA) in Danish children between 1997/1998 and 2003/2004. HPA was assessed objectively by accelerometry. Primarily, overall differences were analyzed as gender and day type specific (i.e. Mon-Thu vs Fri-Sun) levels in HPA. Secondarily, differences were analyzed across socioeconomic gradients defined according to parents' occupation. Data were expressed as total counts per registered time. During the period 1997/1998-2003/2004, no significant differences were observed in the level of HPA during Mon-Thu or Fri-Sun or across socioeconomic gradients. Post hoc analyses indicated a slightly more favorable ratio between the percentages of time spent in light and moderate intensity levels during Mon-Thu in 2003/2004 when compared with 1997/1998. Gender differences in the level of HPA were found to be more distinct during Mon-Thu than during Fri-Sun. This study does not support the idea that Danish children are becoming less physically active. However, a limited statistical power should be considered when interpreting differences across socioeconomic gradients. Boys were found to be more physically active than girls, especially during the weekdays (Friday not included).