Pelegrini A, Klen JA, Costa AM, et al. - Researchers intended to determine if there is an association between sedentary behaviors and bone mass in adolescents. One hundred four adolescent boys and girls, between the ages of 10 and 14, were divided into normal weight and overweight by weight status. Specific sedentary behaviors (time spent on the Internet for school and non-school purposes, using the computer, watching television, and playing videogames) have been evaluated by questionnaire, and the total sedentary behavior time by accelerometry. The authors discovered that adolescents who spend a lot of time in sedentary behavior, particularly using the Internet for non-school purposes, have a higher bone mineral density (BMD) and bone mineral content. On the other hand, normal-weight adolescents who spend more time on the computer have lower BMD.