title: Effect of Ramadan fasting on fuel oxidation during exercise in trained male rugby players.
abstract: OBJECTIVE
  The aim of this study was to assess the effect of Ramadan fasting on substrate oxidation in trained athletes during moderate-intensity exercise.
  
  
  METHODS
  Nine trained men (age: 19+/-2 yr, Height: 1.78+/-0.74 m) were tested on three occasions: during a control period immediately before Ramadan (C), at the end of the first week (Beg-R), and during the fourth week of Ramadan (End-R). On each occasion, they performed submaximal cycle ergometer exercise, with work-rates that were increased progressively (loadings corresponding to 20, 30, 40, 50, 60% of Wmax). Steady-state substrate oxidation was evaluated by indirect calorimetry.
  
  
  RESULTS
  Participants showed significant decreases in body mass and body fat at the end of Ramadan, relative to initial control values (P<0.001). The daily food intake was also reduced during Ramadan (P<0.01). Haemoglobin concentrations and hematocrit were significantly higher at the end-Ramadan, both at rest (P<0.001 and P<0.0001 respectively) and after exercise, (P<0.05 and P<0.01 respectively) compared to control measurements made before Ramadan. At the end of Ramadan, our subjects had increased their fat utilization during exercise. The cross-over was observed at a higher intensity at the End-R (35% vs. 30% of Wmax, P<0.001). For the same power output, the Lipox max was also higher at the End-R, compared to control value (265+/-38 vs. 199.1+/-20 mg/min, P<0.001).
  
  
  CONCLUSIONS
  Ramadan fasting increases the lipid oxidation of trained athletes during submaximal exercise. The increased fat utilisation may be related to decreases in body mass and body fat content.
authors.affiliation: Unité de Recherche de l'Institut Supérieur du Sport et de l'Education Physique, Kef, Tunisie. e.bouhlel@wanadoo.tn
authors.forename: E
authors.initials: E
authors.lastname: Bouhlel
authors.forename: Z
authors.initials: Z
authors.lastname: Salhi
authors.forename: H
authors.initials: H
authors.lastname: Bouhlel
authors.forename: S
authors.initials: S
authors.lastname: Mdella
authors.forename: A
authors.initials: A
authors.lastname: Amamou
authors.forename: M
authors.initials: M
authors.lastname: Zaouali
authors.forename: J
authors.initials: J
authors.lastname: Mercier
authors.forename: X
authors.initials: X
authors.lastname: Bigard
authors.forename: Z
authors.initials: Z
authors.lastname: Tabka
authors.forename: A
authors.initials: A
authors.lastname: Zbidi
authors.forename: R J
authors.initials: RJ
authors.lastname: Shephard
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002149:Energy Intake; D015444:Exercise; D005080:Exercise Test; D005215:Fasting / Q000502:physiology*; D005538:Football; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007514:Islam; D008297:Male; D014416:Tunisia
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin