title: Associations of Physical Activity, Sedentary Time, and Screen Time With Cardiovascular Fitness in United States Adolescents: Results From the NHANES National Youth Fitness Survey.
abstract: Most US adolescents do not meet guidelines of at least 60 daily minutes of moderate- to vigorous-intensity physical activity. In addition, sedentary behaviors among this age group are of increasing concern. This study examined the association of movement behaviors with cardiovascular fitness among US adolescents.
  
  
  
  Data from the 2012 NHANES National Youth Fitness Survey were used to assess the association of movement behaviors (physical activity, sedentary time, screen time) with cardiovascular fitness among adolescent males and females. Multiple logistic regressions were used to test the independent and interactive effects of movement behaviors on cardiovascular fitness.
  
  
  
  Among females, physical activity was directly associated with cardiovascular fitness; no significant association was observed between sedentary behaviors and CVF. Among males, sedentary time moderated the relationship between physical activity and cardiovascular fitness, such that a significant, direct association was only observed among those with high sedentary time (OR: 5.01; 95% CI: 1.60, 15.70).
  
  
  
  Results from this cross-sectional analysis suggest that among female US adolescents, physical activity, but not sedentary behavior, is associated with cardiovascular fitness. Among males, the interaction between physical activity and sedentary time seems to be important for cardiovascular fitness. Longitudinal studies are warranted to confirm these findings.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Porter
authors.forename: Krystin J
authors.initials: KJ
authors.lastname: Matthews
authors.forename: Deborah
authors.initials: D
authors.lastname: Salvo
authors.forename: Harold W
authors.initials: HW
authors.lastname: Kohl
mesh_terms: D000293:Adolescent; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D057185:Sedentary Behavior; D014481:United States
keywords: epidemiology; gender; sedentary behavior