title: Six-minute walking test predicts maximal fat oxidation in obese children.
abstract: BACKGROUND
  Obesity is associated with reduced exercise maximal fat oxidation rate (FATmax), which is generally assessed by cardiopulmonary cycling test. The six-minute walking test (6MWT) presents an alternative method in patients.
  
  
  OBJECTIVE
  The aim of this study was to establish a practical reference equation facilitating the prediction of FATmax from the 6 MWT in obese children of both genders.
  
  
  METHODS
  This study is a cross-sectional study using mixed linear and multiple regression models.
  
  
  METHODS
  Anthropometric measurements were recorded and submaximal cycling test and 6 MWT conducted for 131 school-aged obese children, 68 boys and 63 girls. A multiple regression analysis for FATmax, including six-minute walking distance (6 MWD), anthropometric and cardiac parameters as the dependent variables, was performed for the two genders separately.
  
  
  RESULTS
  Mean 6 MWD and FATmax were 564.9 ± 53.7 m and 126.5 ± 12.1 mg min(-1) for boys and 506.7 ± 55.0 m and 120.7 ± 10.0 mg min(-1) for girls, respectively. The 6MWD, body mass index, Z-score, fat-free mass, waist and hip circumferences (WC and HC), rest heart rate, and systolic and diastolic blood pressures were highly correlated with FATmax for both genders. There was a significant correlation between 6 MWD and FATmax in both boys and girls (r = 0.88 and r = 0.81, P<0.001, respectively). Stepwise regression analyses revealed that the combinations of 6 MWD with HC for boys and 6MWD with WC for girls improved the predictability of the model (R(2) = 0.81 for boys and R(2) = 0.72 for girls; P<0.001).
  
  
  CONCLUSIONS
  In obese children, the 6MWT can be used to predict FATmax when formal test of exercise capacity and gas exchange analysis are unavailable or impractical. It is therefore possible to prescript targeted exercises at FATmax, without performing indirect calorimetry, just from a field test.
authors.affiliation: Laboratory of Cardio-circulatory, Respiratory, and Hormonal Adaptations to Muscular Exercise, Faculty of Medicine Ibn El Jazzar, Sousse, Tunisia.
authors.forename: E
authors.initials: E
authors.lastname: Makni
authors.forename: W
authors.initials: W
authors.lastname: Moalla
authors.forename: Y
authors.initials: Y
authors.lastname: Trabelsi
authors.forename: G
authors.initials: G
authors.lastname: Lac
authors.forename: J F
authors.initials: JF
authors.lastname: Brun
authors.forename: Z
authors.initials: Z
authors.lastname: Tabka
authors.forename: M
authors.initials: M
authors.lastname: Elloumi
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D016138:Walking