Characteristics of the activity pattern in normal weight and overweight boys

Objective. To assess whether the activity pattern differs between normal weight and overweight boys across weekdays and weekend days. Methods. Physical activity was recorded every 2 s by accelerometry in 32 normal weight and 15 overweight boys aged 8-10 years for four weekdays and two weekend days (South-West England 2007). Summary activity measures and activity pattern characteristics (frequency, intensity and duration of >= 4 s (short) and >= 5-min (long) bouts of >= light, >= moderate, >= vigorous, and >= hard activity) were recorded. Results. Normal weight boys accumulated more >= hard activity (p<0.05) but other summary measures did not differ by weight status. However, the activity pattern differed in overweight relative to normal weight boys. The most frequent short bouts were shorter and less intense (p<0.05). All long bouts were less intense and >= moderate long bouts were shorter and less frequent (p<0.05). Overall, less activity was accumulated on weekends (frequency of more intense short bouts, intensity of most frequent long bouts and duration of >= light, >= moderate (and for overweight boys >= vigorous) short bouts dropped-off) (p<0.05). Conclusion. Despite equivalent summary activity measures overweight boys exhibited fewer and shorter bouts, particularly sustained >= moderate bouts, relative to normal weight boys suggesting that the activity pattern may be important for weight control. (C) 2009 Elsevier Inc. All rights reserved.