One-year longitudinal study found a bidirectional relationship between physical activity and sleep disturbance in teenage Estonian girls.

AIM: Studies have shown that physical activity (PA) declines during adolescence, especially among girls. We examined the relationship between changes in PA and sleep disturbance over the school year, including any bidirectional relationship between these two factors.

METHODS: This longitudinal study focused on teenage girls who had a mean age of 13.2 ± 0.2 years at baseline and were drawn from five randomly selected schools in the city of Tartu, Estonia. Sleep disturbance and PA were subjectively assessed using the self-reported 3-Day Physical Activity Recall and the Insomnia Severity Index, at four intervals throughout the school year. Latent growth curve analyses were used to evaluate longitudinal and bidirectional associations between PA and sleep disturbance.

RESULTS: Assessments were carried out at three-monthly intervals from September 2015 to June 2016. Sleep disturbance increased and PA decreased over the school year. At baseline, higher PA was related to lower sleep disturbance. Changes in PA corresponded with changes in sleep disturbance. A negative bidirectional relationship between sleep disturbance and PA over time was also found.

CONCLUSION: These results suggest that increasing PA may be an effective strategy for improving the quality of sleep in girls during early adolescence.