Latent Profiles of Physical Activity and Sedentary Behavior in Elementary School-Age Youth:Associations With Health-Related Quality of Life.

Objective: The objectives were to identify and describe profiles of elementary school-age youth based on objective measurements of total time spent in moderate-to-vigorous physical activity (MVPA) and sedentary behavior (SB) and in bouts of the activities, to examine predictors of profiles, and to examine whether profiles were differentially associated with physical and psychosocial health-related quality of life (HRQOL).

Methods: Participants included 204 youth (aged 8-11 years) who wore accelerometers to gather objective activity data. The average proportion of time in MVPA and SB and average proportion of time in MVPA and SB bouts were used for analyses. Participants completed a self-report measure of HRQOL. Latent variable mixture modeling was conducted.

Results: Overall, participants did not meet the MVPA guideline (M = 50.7 min) and spent 47% of waking hours in SB, indicating that elementary school is a critical developmental period to study activity levels. Three profiles emerged: "Active," "Inactive," and "Moderate." Boys were significantly more likely to be in the Active profile than the other profiles, and older youth were significantly more likely to be in the Inactive profile. After controlling for child sex and age, participants in the Active profile reported significantly higher psychosocial HRQOL than the participants in the other profiles; however, no significant differences were found in physical HRQOL.

Conclusions: Identification of these naturally occurring profiles suggests need for interventions early in development focused on increasing the intensity of physical activity from light to moderate-to-vigorous for at least 60 min per day as way to improve psychosocial HRQOL.