title: Temporal Associations Between Sleep and Physical Activity Among Overweight/Obese Youth.
abstract: Examine average interindividual and temporal intraindividual associations between time of sleep onset (sleep onset), total sleep time (TST), and minutes in moderate-to-very-vigorous physical activity per hour (MVPA/h) among overweight/obese youth.
  
  
  
  Overweight/obese youth (n = 134; 7-12 years) wore an accelerometer for 16+ hr/day, 5-7 days, which provided daily objective estimates of MVPA/h, TST, and sleep onset.
  
  
  
  Multilevel models revealed an intraindividual effect of TST, such that nights with longer TST preceded less MVPA/h during the midnight-to-midnight monitoring period; a significant random effect qualified this relationship. Average interindividual TST did not predict mean MVPA/h, whereas sleep onset significantly predicted mean MVPA/h.
  
  
  
  Later time of sleep onset (as opposed to TST) was the strongest predictor of group-level decreased physical activity. At the individual level, longer TST than usual predicted less MVPA/h than usual. Results suggest the need for more person-centered research and a greater focus on sleep timing among youth.
authors.affiliation: Department of Clinical and Health Psychology, University of Florida and kkrietsch@phhp.ufl.edu.
authors.forename: Kendra N
authors.initials: KN
authors.lastname: Krietsch
authors.affiliation: Department of Clinical and Health Psychology, University of Florida and.
authors.forename: Bridget
authors.initials: B
authors.lastname: Armstrong
authors.affiliation: Department of Health Psychology, University of Missouri.
authors.forename: Christina S
authors.initials: CS
authors.lastname: McCrae
authors.affiliation: Department of Clinical and Health Psychology, University of Florida and.
authors.forename: David M
authors.initials: DM
authors.lastname: Janicke
mesh_terms: D002648:Child; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009765:Obesity / Q000503:physiopathology / Q000523:psychology; D050177:Overweight / Q000503:physiopathology / Q000523:psychology*; D012890:Sleep; D013997:Time Factors
keywords: child; exercise; pediatric; physical activity; sleep; temporal