Associations between physical activity and sedentary behavior with sleep quality and quantity in young adults.

Objectives: Intensity and duration of physical activity (PA) and sedentary behavior are individually associated with sleep, but their independent associations are poorly characterized. The objectives of this study were to determine if PA and/or sedentary behavior are/is associated with sleep quality and/or quantity in a young adult sample.

Design: Cross-sectional.

Setting: Montreal, Canada.

Participants: Participants (n=658) from the Nicotine Dependence in Teens Study.

Measurements: PA measures included total minutes of light, moderate, and vigorous PA in the past week; sedentary measures included number of hours per day watching television (TV) and using the computer for leisure activities in the past week. Sleep measures included (1) the Pittsburgh Sleep Quality Index, which assesses sleep quality in the past month, and (2) number of hours of sleep per night in the past month. Data were analyzed using multiple logistic regression adjusting for age, sex, and mother's education.

Results: In multivariable analyses, each additional hour of TV and computer use per day was associated with a 17% and 13% increase, respectively, in the odds of reporting poor sleep quality. After additionally adjusting for PA, the association between TV use and poor sleep quality remained significant (odds ratio: 1.15, 95% confidence interval: 1.01-1.28). Sedentary behavior was not associated with sleep quantity. PA intensity and duration were not associated with sleep quality or quantity.

Conclusions: More time spent doing sedentary activities was associated with poorer sleep quality, but PA was not associated. Clinicians treating young adults with sleep problems should inquire about sedentary behavior.