Sleep and adjustment in adolescence: physical activity as a moderator of risk

We investigated physical activity as a moderator of relations between sleep duration and quality and adolescents' internalizing and externalizing problems.

The study used a cross-sectional design.

Participants were recruited from small towns and semi-urban communities in Alabama.

The sample was comprised of 235 adolescents (M_age = 15.78 years, SD = 9.60 months) who were diverse in sex (53% female), race/ethnicity (34% Black/African American, 66% White), and socioeconomic status.

Sleep duration (actual sleep minutes), efficiency (minutes/total sleep period), and latency (minutes from sleep attempt to onset) were examined with actigraphs for 1 week. Youth reported on their physical activity levels and internalizing and externalizing problems.

Interactions between sleep and physical activity emerged in the prediction of adolescents' internalizing and externalizing problems. Supportive of moderation effects, adolescents with shorter or poorer-quality sleep in conjunction with less physical activity showed the highest levels of internalizing and externalizing problems. Demonstrative of protective effects, adolescents with more physical activity had lower levels of internalizing and externalizing problems regardless of their sleep duration or quality.

Findings illustrate that not all youth are at equal risk for adjustment problems when they experience short or poor-quality sleep, suggesting the importance of examining both bioregulatory and environmental factors in understanding adolescent adjustment.