title: Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents.
abstract: BACKGROUND
  Little is known about how the intensity of exercise influences cardiovascular fitness and body composition, especially in obese adolescents.
  
  
  OBJECTIVE
  Our goal was to determine the effects of physical training intensity on the cardiovascular fitness, percentage of body fat (%BF), and visceral adipose tissue (VAT) of obese adolescents.
  
  
  METHODS
  Obese 13-16-y-olds (n = 80) were assigned to 1) biweekly lifestyle education (LSE), 2) LSE + moderate-intensity physical training, or 3) LSE + high-intensity physical training. The intervention lasted 8 mo. Physical training was offered 5 d/wk, and the target energy expenditure for all subjects in physical training groups was 1047 kJ (250 kcal)/session. Cardiovascular fitness was measured with a multistage treadmill test, %BF with dual-energy X-ray absorptiometry, and VAT with magnetic resonance imaging.
  
  
  RESULTS
  The increase in cardiovascular fitness in the high-intensity physical training group, but not in the moderate-intensity group, was significantly greater than that in the LSE alone group (P = 0.009); no other comparisons of the 3 groups were significant. Compared with the LSE alone group, a group composed of subjects in both physical training groups combined who attended training sessions >or=2 d/wk showed favorable changes in cardiovascular fitness (P < 0.001), %BF (P = 0.001), and VAT (P = 0.029). We found no evidence that the high-intensity physical training was more effective than the moderate-intensity physical training in enhancing body composition.
  
  
  CONCLUSIONS
  The cardiovascular fitness of obese adolescents was significantly improved by physical training, especially high-intensity physical training. The physical training also reduced both visceral and total-body adiposity, but there was no clear effect of the intensity of physical training.
authors.affiliation: Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta, GA 30912, USA. bgutin@mail.mcg.edu
authors.forename: Bernard
authors.initials: B
authors.lastname: Gutin
authors.forename: Paule
authors.initials: P
authors.lastname: Barbeau
authors.forename: Scott
authors.initials: S
authors.lastname: Owens
authors.forename: Christian R
authors.initials: CR
authors.lastname: Lemmon
authors.forename: Mara
authors.initials: M
authors.lastname: Bauman
authors.forename: Jerry
authors.initials: J
authors.lastname: Allison
authors.forename: Hyun-Sik
authors.initials: HS
authors.lastname: Kang
authors.forename: Mark S
authors.initials: MS
authors.lastname: Litaker
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D001823:Body Composition; D002320:Cardiovascular Physiological Phenomena; D015444:Exercise / Q000502:physiology*; D006801:Humans; D009765:Obesity / Q000473:pathology* / Q000503:physiopathology*; D010807:Physical Endurance / Q000502:physiology; D010809:Physical Fitness; D014781:Viscera