title: Exploring New Relationships Between Physical Activity Volume and Intensity and Cardiometabolic Risk in U.S. Adolescents.
abstract: BACKGROUND
  Associations between physical activity (PA) intensity and volume and adolescents' cardiometabolic health have research, policy, and practice implications. This study compares associations between cardiometabolic risk factors and 1) moderate-to-vigorous PA (MVPA) minutes versus total PA volume (accelerometer-derived total activity counts, TAC) and 2) light PA volume (counts at light intensity, L-TAC) versus moderate-to-vigorous PA volume (counts at moderate-to-vigorous intensity, MV-TAC).
  
  
  METHODS
  2105 adolescents from 2003- 2006 NHANES were included. Independent variables were MVPA minutes, TAC, L-TAC, and MV-TAC. Regression models tested associations between PA variables and continuous metabolic risk index (CMRI), waist circumference, systolic and diastolic blood pressure, HDL, insulin, and triglycerides.
  
  
  RESULTS
  TAC demonstrated a slightly stronger inverse association with CMRI (P = .004) than did MVPA (P = .013). TAC and MVPA were both associated with systolic and diastolic pressure, HDL, and insulin; associations were similar or slightly stronger for TAC. L-TAC and MV-TAC were both associated with CMRI and HDL. Only L-TAC was associated with diastolic pressure. Only MV-TAC was associated with waist circumference, systolic pressure, and insulin.
  
  
  CONCLUSIONS
  Compared with MVPA minutes, TAC demonstrates similar or slightly stronger associations with cardiometabolic risk factors. L-TAC and MV-TAC appear similarly associated with adolescents' clustered risk but differently associated with individual risk factors.
authors.affiliation: Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Hatfield
authors.forename: Virginia R
authors.initials: VR
authors.lastname: Chomitz
authors.forename: Kenneth
authors.initials: K
authors.lastname: Chui
authors.forename: Jennifer
authors.initials: J
authors.lastname: Sacheck
authors.forename: Christina D
authors.initials: CD
authors.lastname: Economos
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D001794:Blood Pressure / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002320:Cardiovascular Physiological Phenomena; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D009749:Nutrition Surveys; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood*; D014481:United States; D055105:Waist Circumference / Q000502:physiology
chemical_list: D007328:Insulin; D014280:Triglycerides