title: Physical activity intensity and cardiometabolic risk in youth.
abstract: OBJECTIVE
  To determine the association between physical activity (PA) intensities and cardiometabolic risk factors in youth.
  
  
  METHODS
  Cross-sectional study using data from the 2008 Healthy Hearts Prospective Cohort Study of Physical Activity and Cardiometabolic Health in Youth.
  
  
  METHODS
  Rural and urban communities in Alberta, Canada.
  
  
  METHODS
  A convenience sample of 605 youth aged 9 to 17 years. Youth were on average aged 12.1 years, 248 were boys (41%), and 157 were overweight or obese (26%).
  
  
  METHODS
  Actical accelerometer-measured PA intensity.
  
  
  METHODS
  The primary outcome was body mass index (calculated as weight in kilograms divided by height in meters squared) z score. Secondary outcome measures included waist circumference, systolic blood pressure, and cardiorespiratory fitness (maximal oxygen consumption [[Vdot]O2max]).
  
  
  RESULTS
  Body mass index z score, waist circumference, and systolic blood pressure decreased and [Vdot]O2max increased in a dose-response manner across tertiles of vigorous PA (adjusted P < .001). No significant differences in cardiometabolic risk factors were seen across tertiles of moderate or light PA in multivariable analyses. Achieving more than 7 minutes of vigorous PA daily was associated with a reduced adjusted odds ratio of overweight status (0.56; 95% CI, 0.33-0.95) and elevated systolic blood pressure (0.36; 95% CI, 0.16-0.79). The odds of overweight status and elevated blood pressure decreased with increasing time and intensity of PA.
  
  
  CONCLUSIONS
  Only vigorous PA was consistently associated with lower levels of waist circumference, body mass index z score, systolic blood pressure, and increased cardiorespiratory fitness in youth. These findings underscore the importance of vigorous PA in guidelines for children and adolescents.
authors.affiliation: Manitoba Institute of Child Health,Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Canada.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Hay
authors.forename: Katerina
authors.initials: K
authors.lastname: Maximova
authors.forename: Anita
authors.initials: A
authors.lastname: Durksen
authors.forename: Valerie
authors.initials: V
authors.lastname: Carson
authors.forename: Randi Lynn
authors.initials: RL
authors.lastname: Rinaldi
authors.forename: Brian
authors.initials: B
authors.lastname: Torrance
authors.forename: Geoff D C
authors.initials: GD
authors.lastname: Ball
authors.forename: Sumit R
authors.initials: SR
authors.lastname: Majumdar
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Plotnikoff
authors.forename: Paul
authors.initials: P
authors.lastname: Veugelers
authors.forename: Normand G
authors.initials: NG
authors.lastname: Boulé
authors.forename: Paul
authors.initials: P
authors.lastname: Wozny
authors.forename: Linda
authors.initials: L
authors.lastname: McCargar
authors.forename: Shauna
authors.initials: S
authors.lastname: Downs
authors.forename: Richard
authors.initials: R
authors.lastname: Lewanczuk
authors.forename: Jonathan
authors.initials: J
authors.lastname: McGavock
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D000416:Alberta; D001794:Blood Pressure; D015992:Body Mass Index; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D050177:Overweight / Q000503:physiopathology / Q000517:prevention & control; D010101:Oxygen Consumption; D011446:Prospective Studies; D012306:Risk; D013997:Time Factors; D055105:Waist Circumference