title: The effects of low and high glycemic index 24-h recovery diets on cycling time trial performance.
abstract: OBJECTIVE
  The present study investigated the effects of high and low glycemic index (GI) 24 h recovery meals on the physiological responses and subsequent athletic performance, following a glycogen depleting protocol.
  
  
  METHODS
  Ten well trained cyclists (age, 33.6±7.4y, height, 175.3±7.6 cm, weight 74.5±8.2 kg, and VO(2max), 60.5±6.0 ml∙kg(-1)∙min(-1)) participated in two trials in a randomized cross- over design. On day 1, subjects performed a glycogen depleting protocol after which they then consumed either high or low GI recovery diets over the next 24 h, which provided 8 g.kgBW(-1) of carbohydrate. On day 2, the subjects returned to the laboratory, 2- 3 h postprandial, to perform a 40 km time trial (TT) on the Velotron cyclePro© ergometer.
  
  
  RESULTS
  No difference was observed in TT performance times between the high GI (93. 5±9.29 min) trial and the low GI (90.7±11.1 min) trial (t=1.1; P=0.35). Additionally, no differences in carbohydrate (F=1.1, P=0.37) fat (F=1.1, P=0.40) oxidation or blood glucose concentration (F=0.9, P=0.5) was observed.
  
  
  CONCLUSIONS
  The results of the present study suggest that the ingestion of a high GI carbohydrate 24 h recovery diet following glycogen depleting exercise, has no greater effect on endurance performance than consuming a low GI carbohydrate 24 h recovery diet. It may be concluded from these results that, provided enough carbohydrate is consumed during a 24 h recovery period, there is no difference in subsequent endurance performance.
authors.affiliation: Department of Sport, Health and Exercise Science, University of Hull, Hull, UK.
authors.forename: L J S
authors.initials: LJ
authors.lastname: Moore
authors.forename: A
authors.initials: A
authors.lastname: Midgley
authors.forename: R
authors.initials: R
authors.lastname: Vince
authors.forename: L R
authors.initials: LR
authors.lastname: McNaughton
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D038321:Glycemic Index; D006801:Humans; D008297:Male; D010807:Physical Endurance / Q000502:physiology
chemical_list: D004040:Dietary Carbohydrates