School schedule affects sleep, but not physical activity, screen time and diet behaviors

Abstract

Background: Behavioral changes during adolescence are affected by biological and social aspects. However, environment aspects, which are beyond adolescents' control, also contribute to behavior adoption, and school may have a significant impact in these behaviors. This cross-sectional study aims to investigate how lifestyle behaviors are associated with the school shift attended by high school students.

Methods: The sample comprised 635 high school students (51.2% girls, 16.33 ± 1.0 years old) from Southern Brazil. Physical activities of different intensities (light and moderate-to-vigorous), sedentary behaviors, and sleep (duration, efficiency, and timing) were measured using accelerometers. Engagement in sport and non-sport activities, screen time indicators, and diet were self-reported. Linear models were fitted to compare each lifestyle behavior between the two school shifts.

Results: Students attending the afternoon shift slept (β = 01:29 95%CI 01:13; 01:46) and woke up later (β = 01.41 95%CI 01:27; 01:54), and had a longer sleep duration (β = 00:12 95%CI 0:02; 00:21) than those attending the morning shift. However, the sleep efficiency of those in the afternoon shift was lower than their peers in the morning shift (β = -1.89 95%CI -3.01; -0.77).

Conclusions: School schedule was associated with sleep behaviors of adolescents, but not with other lifestyle behaviors.

Keywords: Accelerometer; Lifestyle behaviors; Scholars; Sedentary behavior.