title: Exercise energy expenditure and postprandial lipemia in girls.
abstract: OBJECTIVE
  This study aimed to examine the effect of 30 and 60 min of moderate-intensity treadmill walking on postprandial triacylglycerol concentrations ([TAG]) in healthy girls.
  
  
  METHODS
  Eighteen 10- to 14-yr-old girls (mean ± SD; body mass = 48 ± 11 kg, body fat = 19.0 ± 4.6%, peak oxygen uptake [V˙O2] = 47 ± 6 mL·kg·min) completed three 2-d trials in a counterbalanced crossover design, each separated by 14 d. On day 1, they rested (CON) or completed 30 min (EX30) or 60 min (EX60) of intermittent treadmill exercise at 56% peak V˙O2, inducing energy expenditures of 777 and 1536 kJ (186 and 367 kcal), respectively. On day 2, after a 12-h fast, a capillary blood sample was taken for fasting [TAG] before a high-fat milkshake (80 kJ·kg(-1) body mass) was consumed. Further blood samples were taken hourly over a 6-h postprandial rest period for [TAG]. ANOVA and Student's t-tests were used to analyze the data.
  
  
  RESULTS
  Fasting [TAG] was lower in EX60 than CON (95% confidence interval [CI] = -0.36 to 0.04, effect size (ES) = 0.41) and EX30 (95% CI = -0.47 to 0.04, ES = 0.46); all group mean concentrations were low (≤ 0.90 mmol·L(-1)). The main effect for condition revealed differences in postprandial [TAG] over time (ES = 0.36). The EX60 total area under the [TAG] versus time curve was lower than CON (95% CI = -2.66 to -0.04, ES 0.40) and EX30 (95% CI = -2.11 to 0.15, ES = 0.30); CON and EX30 were similar (95% CI = -1.44 to 0.71, ES = 0.10).
  
  
  CONCLUSIONS
  This study demonstrates that 60 min but not 30 min of moderate treadmill exercise, with a gross energy expenditure of 1536 kJ (367 kcal), attenuated postprandial [TAG] in girls.
authors.affiliation: Paediatric Exercise Physiology Research Group, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM.
authors.forename: Keith
authors.initials: K
authors.lastname: Tolfrey
authors.forename: Alex
authors.initials: A
authors.lastname: Engstrom
authors.forename: Caoileann
authors.initials: C
authors.lastname: Murphy
authors.forename: Alice
authors.initials: A
authors.lastname: Thackray
authors.forename: Robert
authors.initials: R
authors.lastname: Weaver
authors.forename: Laura A
authors.initials: LA
authors.lastname: Barrett
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D018592:Cross-Over Studies; D004032:Diet; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005215:Fasting / Q000097:blood; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood; D019518:Postprandial Period; D013997:Time Factors; D014280:Triglycerides / Q000097:blood*; D016138:Walking / Q000502:physiology
chemical_list: D001786:Blood Glucose; D014280:Triglycerides