title: Weekday and weekend sedentary time and physical activity in differentially active children.
abstract: OBJECTIVE
  To investigate whether weekday-weekend differences in sedentary time and specific intensities of physical activity exist among children categorised by physical activity levels.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Seven-day accelerometer data were obtained from 810 English children (n=420 girls) aged 10-11 years. Daily average minday(-1) spent in moderate to vigorous physical activity were calculated for each child. Sex-specific moderate to vigorous physical activity quartile cut-off values categorised boys and girls separately into four graded groups representing the least (Q1) through to the most active (Q4) children. Sex- and activity quartile-specific multilevel linear regression analyses analysed differences in sedentary time, light physical activity, moderate physical activity, vigorous physical activity, and moderate to vigorous physical activity between weekdays and weekends.
  
  
  RESULTS
  On weekdays Q2 boys spent longer in light physical activity (p<0.05), Q1 (p<0.001), Q2 boys (p<0.01) did significantly more moderate physical activity, and Q1-Q3 boys accumulated significantly more vigorous physical activity and moderate to vigorous physical activity than at weekends. There were no significant differences in weekday and weekend sedentary time or physical activity for Q4 boys. On weekdays Q2 and Q3 girls accumulated more sedentary time (p<0.05), Q1 and Q2 girls did significantly more moderate physical activity (p<0.05), and Q1-Q3 girls engaged in more vigorous physical activity (p<0.05) and more moderate to vigorous physical activity (p<0.01) than at weekends. Q4 girls' sedentary time and physical activity varied little between weekdays and weekends.
  
  
  CONCLUSIONS
  The most active children maintained their sedentary time and physical activity levels at weekends, while among less active peers weekend sedentary time and physical activity at all intensities was lower. Low active children may benefit most from weekend intervention strategies.
authors.affiliation: The Physical Activity Exchange, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK. Electronic address: s.j.fairclough@ljmu.ac.uk.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Fairclough
authors.affiliation: The Physical Activity Exchange, Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK.
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Boddy
authors.affiliation: Research Centre in Applied Sports, Technology, Exercise and Medicine, College of Engineering, Swansea University, UK.
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Mackintosh
authors.affiliation: Department of Musical, Plastic and Movement Expression Didactics, University of Valencia, Spain.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Valencia-Peris
authors.affiliation: Department of Physical Education, University Complutense of Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Ramirez-Rico
mesh_terms: D061725:Accelerometry; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D005082:Physical Exertion; D057185:Sedentary Behavior; D012737:Sex Factors; D013997:Time Factors
keywords: Child; Health; High active; Motor activity; Multilevel analysis; Time-of-week differences