Gender and age differences in relation to the recommendations of physical activity among Norwegian children and youth

The Norwegian physical activity recommendations for children and youth state that there should be a minimum of 60 min of physical activity of at least moderate intensity every day. The purpose of this study was to evaluate objectively the level of physical activity in a representative cohort of urban children and youth in Norway with regard to these recommendations. Four hundred and ten 9-year-old and 350 15-year-old boys and girls from the Oslo region participated. Physical activity was registered for 4 consecutive days using the Computer Science and Application activity monitor. The results showed that 86.2% of the 9-year-olds and 55.4% of the 15-year-olds met the recommendations. Furthermore, the activity level was significantly (P < 0.0001) higher among boys than girls of both age groups and significantly (P < 0.001) lower in the oldest cohort than in the youngest one. All participants were less active during the weekend than during the weekdays (P < 0.05). In conclusion, a number of urban children and youth do not fulfill the Norwegian physical activity recommendations, especially among the 15-year-olds. It is therefore important to provide action towards those children and youth who are least physically active and simultaneously prevent the general decline in physical activity.