title: The physical activity level of Mexican children decreases upon entry to elementary school.
abstract: OBJECTIVE
  To compare the physical activity patterns of a cohort of Mexican children in kindergarten (K), first (1ES) and second grade (2ES) of elementary school.
  
  
  METHODS
  The physical activity of 217 children (123 girls and 94 boys) aged 5-6 years was measured (five full-day triaxial accelerometry) annually.Weekday and weekend moderate/ vigorous physical activity (MVPA) and school and off-school MVPA was calculated. Comparisons between surveys were made using longitudinal multilevel generalized linear models.
  
  
  RESULTS
  Weekday MVPA was 22 and 37 min/d lower for 1ES (p=0.06) and 2ES (p<0.01), respectively, compared to K. School MVPA for 1ES and 2ES was 37 (-5.0 min/h) and 40% (-5.5 min/h) (p<0.001) lower, respectively, compared to K. No differences were found between weekend and off-school MVPA among school stages (p>0.5).
  
  
  CONCLUSIONS
  MVPA was significantly reduced from K to ES,in part because of a decline in MVPA during school activities. Interventions targeted to school environment modifications should be promoted.
authors.affiliation: Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Jáuregui
authors.forename: Salvador
authors.initials: S
authors.lastname: Villalpando
authors.forename: Eduardo
authors.initials: E
authors.lastname: Rangel-Baltazar
authors.forename: Jessica
authors.initials: J
authors.lastname: Castro-Hernández
authors.forename: Yaveth
authors.initials: Y
authors.lastname: Lara-Zamudio
authors.forename: Ignacio
authors.initials: I
authors.lastname: Méndez-Gómez-Humarán
mesh_terms: D000054:Acceleration; D000886:Anthropometry; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D004522:Educational Status; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008019:Life Style; D008297:Male; D008800:Mexico; D009035:Mothers; D009043:Motor Activity; D012574:Schools; D012959:Socioeconomic Factors; D013334:Students / Q000706:statistics & numerical data*