title: Physical activity levels of normal-weight and overweight girls and boys during primary school recess.
abstract: OBJECTIVE
  This study aimed to compare moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) in normal-weight and overweight boys and girls during school recess.
  
  
  METHODS
  Four hundred twenty children, age 6 to 10 years, were randomly selected from 25 schools in England. Three hundred seventy-seven children completed the study. BMI was calculated from height and weight measurements, and heart rate reserve thresholds of 50% and 75% reflected children's engagement in MVPA and VPA, respectively.
  
  
  RESULTS
  There was a significant main effect for sex and a significant interaction between BMI category and sex for the percent of recess time spent in MVPA and VPA. Normal-weight girls were the least active group, compared with overweight boys and girls who were equally active. Fifty-one boys and 24 girls of normal weight achieved the 40% threshold; of these, 30 boys and 10 girls exceeded 50% of recess time in MVPA. Eighteen overweight boys and 22 overweight girls exceeded the 40% threshold, whereas 8 boys and 8 girls exceeded the 50% threshold.
  
  
  CONCLUSIONS
  Overweight boys were significantly less active than their normal-weight male counterparts; this difference did not hold true for girls. Even though nearly double the number of normal-weight children achieved the 40% of MVPA during recess compared with overweight children, physical activity promotion in school playgrounds needs to be targeted not only at overweight but at other health parameters, as 40 overweight children met the 40% MVPA target proposed for recess.
authors.affiliation: Research Institute for Sports and Exercise Sciences, 15-21 Webster Street, Liverpool John Moores University, Liverpool, UK. G.Stratton@ljmu.ac.uk
authors.forename: Gareth
authors.initials: G
authors.lastname: Stratton
authors.forename: Nicola D
authors.initials: ND
authors.lastname: Ridgers
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Fairclough
authors.forename: David J
authors.initials: DJ
authors.lastname: Richardson
mesh_terms: D001835:Body Weight; D002648:Child; D005260:Female; D006339:Heart Rate; D006801:Humans; D007899:Leisure Activities; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D050177:Overweight / Q000502:physiology*; D012574:Schools