Adolescents are meant to spend a large part of their time practicing a hobby or sport, but currently there is a decline in their level of physical activity and sport both inside and outside schools, which can lead to a risk of obesity. The objective of the present study was to examine physical activity in obese adolescents within the school establishments of the province of Bejaia (northeastern Algeria).

To determine the physical activity level (PAL) in the school population, a sample of 3,038 students with obesity comprising 1,635 girls and 1,403 boys was selected. The study focused on (a) the comparison of the intensity of physical activities practiced by girls and boys, (ii) the determination of the duration, intensity, and level of physical activity.

The results show that obese girls are less active than obese boys at all ages (from 11 to 23 years) and in all locations; PALs was steady with increasing age for girls, while PALs increase with age in boys from 17 to 21. We found that some factors are associated with a decrease in PAL, such as the time spent watching television. Doing only 30 min of physical activity once a week is associated with an increase in sedentary behavior. The mean PALs of middle school (1.54) and high school (1.50) girls were lower than those observed for middle school (1.75) and high school (1.65) boys.

Our results show that obese girls are less active than obese boys and spend time watching television and practicing sports only at school.