A decline in adolescents’ moderate-to-vigorous
physical activity (MVPA) and the increase in their sedentary behavior (SB) have
been registered all over the world. In order to increase the MVPA and reduce
the SB of adolescents, their day has been analyzed by segments of time,
verifying the contribution of each to the daily recommendation of 60
minutes/day. Previous studies have been centered only in physical activity
markers, but the SB variables were not compared nor the segments of the
school-recess with the out-of-school period or with the weekend. This study
aimed to examine the intra- and inter-days differences in the objectively
measured levels of PA and SB in adolescents. A sample of 156 Chilean school
students (87 boys and 69 girls; M age=13.41; SD=.67 years) participated in the
present study. Participants’ PA and SB were objectively measured by a GT3X
accelerometer. Overall results showed that only 14% and 9% of Chilean
adolescents achieved the daily recommendation of 60 minutes of MVPA on weekdays
and the weekend, respectively. School recess was found the best moment for
developing MVPA, followed by out-of-school time, and ending with weekend days
presenting the worst scenario. Regarding the SB, Chilean adolescents were
involved in SB 69.39% of the time on weekdays, and over 70% during the weekend.
Different strategies are discussed in order to increase the MVPA and to
decrease SB in each segment of a day.