title: Physical activity during recess among 13-14 year old Mexican girls.
abstract: BACKGROUND
  Physical activity patterns during recess have been poorly described among adolescents. Physical activity levels could be captured the most accurately using a combination of instruments. The purposes of this study were to describe the physical activity patterns during school recess in a sample of 13-14 year old Mexican girls, to examine differences in these patterns as assessed using three physical activity measurement instruments and to understand the influence of body weight status on the observed associations.
  
  
  METHODS
  The study population included seventy-two female adolescents from a private school in Mexico City. Three different instruments were used to monitor physical activity patterns during the recess break including an accelerometer, direct observation (SOFIT instrument), and a physical activity recall. Descriptive analyses were used to characterize physical activity patterns, and one-way ANOVA was used to examine differences across physical activity instruments.
  
  
  RESULTS
  Based on the accelerometer data, more than 90% of the recess period was spent at a light or sedentary intensity. Based on SOFIT and recall, the two most frequent activities were standing and walking. There was a significant difference (p < 0.05) between the three instruments for time spent in all physical activity intensities.
  
  
  CONCLUSIONS
  The large amount of time spent in light and sedentary intensity activities during recess indicates the necessity to intervene upon this opportunity for adolescents to engage in more vigorous forms of physical activity.
authors.affiliation: School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada. catalina.medina@insp.mx.|Mexican National Institute of Public Health, Av. Universidad 655, Col. Sta. María Ahuacatitlán, 62100, Cuernavaca, Morelos, Mexico. catalina.medina@insp.mx.
authors.forename: Catalina
authors.initials: C
authors.lastname: Medina
authors.affiliation: Mexican National Institute of Public Health, Av. Universidad 655, Col. Sta. María Ahuacatitlán, 62100, Cuernavaca, Morelos, Mexico. sbarquera@insp.mx.
authors.forename: Simon
authors.initials: S
authors.lastname: Barquera
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA. Peter.Katzmarzyk@pbrc.edu.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Katzmarzyk
authors.affiliation: School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada. ian.janssen@queensu.ca.
authors.forename: Ian
authors.initials: I
authors.lastname: Janssen
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D006801:Humans; D011939:Mental Recall; D008800:Mexico; D009043:Motor Activity; D019370:Observation; D012574:Schools; D057185:Sedentary Behavior; D012737:Sex Factors