title: Patterns of moderate and vigorous physical activity in obese and overweight compared with non-overweight children.
abstract: OBJECTIVE
  We determined whether overweight and obese children performed less combined moderate and vigorous physical activity (MVPA), less vigorous physical activity (VPA) alone, and had distinct patterns of sustained MVPA or VPA compared with non-overweight children.
  
  
  METHODS
  We monitored 106 children (aged 8 to 10 years) for 7 consecutive days using accelerometers. Differences in mean daily MVPA and VPA were assessed by comparing non-overweight (NOW) with overweight and obese (OW/OB) participants using descriptive statistics and regression analysis. We used an algorithm to identify periods of consecutive minutes where MVPA or VPA was continuous, called bouts. We then compared the bouts performed by NOW versus OW and OB participants with respect to the mean of the counts·minute(-1) for the minutes included in the bout, their mean length in minutes, and the number of MVPA bouts performed in sequence.
  
  
  RESULTS
  The non-overweight group averaged 143 minutes of MVPA per day versus 120 minutes among the OW/OB (p=0.004). The OW/OB group had fewer MVPA bouts per day compared with the NOW (11.6 versus17.6, p=0.012). Fewer VPA bouts were associated with greater body mass index z-score (p<0.001). The NOW children had more intense body motion during MVPA bouts and performed a greater proportion of MVPA bouts in sequences of five or more consecutive bouts, compared with the OW/OB (p=0.05 and p=0.002, respectively).
  
  
  CONCLUSIONS
  In addition to performing less physical activity, we found that obese and overweight children had distinct patterns of MVPA and VPA bouts compared with non-overweight peers.
authors.affiliation: Department of Pediatrics, Yale University School of Medicine, New Haven, CT , USA. karen.dorsey@yale.edu
authors.forename: Karen B
authors.initials: KB
authors.lastname: Dorsey
authors.forename: Jeph
authors.initials: J
authors.lastname: Herrin
authors.forename: Harlan M
authors.initials: HM
authors.lastname: Krumholz
mesh_terms: D056044:Actigraphy / Q000379:methods; D001741:Black or African American; D000367:Age Factors; D000465:Algorithms; D015992:Body Mass Index; D002648:Child; D003237:Connecticut; D003430:Cross-Sectional Studies; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D009043:Motor Activity; D009765:Obesity / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology*; D050177:Overweight / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology*; D013997:Time Factors