Evaluating Relationships Between Sleep and Next-Day Physical Activity in Young Women.

Background: To evaluate the relationship between sleep and next-day physical activity (PA) under free-living conditions in women.

Methods: Sleep and PA were measured objectively for 7 consecutive days by accelerometry in 330 young adult women (aged 17-25 y). A structural equation model was used to evaluate the relationship between the driving factor of sleep (total sleep or morning wake time) and the amount of nonsleep sedentary (SED) and moderate to vigorous physical activity (MVPA) each day.