title: Enhanced Endurance Performance by Periodization of Carbohydrate Intake: "Sleep Low" Strategy.
abstract: OBJECTIVE
  We investigated the effect of a chronic dietary periodization strategy on endurance performance in trained athletes.
  
  
  METHODS
  Twenty-one triathletes (V˙O2max: 58.7 ± 5.7 mL·min(-1)·kg(-1)) were divided into two groups: a "sleep-low" (SL) (n = 11) and a control (CON) group (n = 10) consumed the same daily carbohydrate (CHO) intake (6 g·kg(-1)·d(-1)) but with different timing over the day to manipulate CHO availability before and after training sessions. The SL strategy consisted of a 3-wk training-diet intervention comprising three blocks of diet-exercise manipulations: 1) "train-high" interval training sessions in the evening with high-CHO availability, 2) overnight CHO restriction ("sleeping-low"), and 3) "train-low" sessions with low endogenous and exogenous CHO availability. The CON group followed the same training program but with high CHO availability throughout training sessions (no CHO restriction overnight, training sessions with exogenous CHO provision).
  
  
  RESULTS
  There was a significant improvement in delta efficiency during submaximal cycling for SL versus CON (CON, +1.4% ± 9.3%; SL, +11% ± 15%, P < 0.05). SL also improved supramaximal cycling to exhaustion at 150% of peak aerobic power (CON, +1.63% ± 12.4%; SL, +12.5% ± 19.0%; P = 0.06) and 10-km running performance (CON, -0.10% ± 2.03%; SL, -2.9% ± 2.15%; P < 0.05). Fat mass was decreased in SL (CON, -2.6 ± 7.4; SL, -8.5% ± 7.4% before; P < 0.01), but not lean mass (CON, -0.22 ± 1.0; SL, -0.16% ± 1.7% PRE).
  
  
  CONCLUSIONS
  Short-term periodization of dietary CHO availability around selected training sessions promoted significant improvements in submaximal cycling economy, as well as supramaximal cycling capacity and 10-km running time in trained endurance athletes.
authors.affiliation: 1French National Institute of Sport, Expertise and Performance (INSEP), Laboratory of Sport, Expertise and Performance, Paris, FRANCE; 2University of Nice Sophia-Antipolis, Laboratory of Human Motricity, Education, Sport and Health, Nice, FRANCE; 3Sports Nutrition, Australian Institute of Sport (AIS), Belconnen, AUSTRALIA; 4Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Melbourne, Victoria, AUSTRALIA; 5Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UNITED KINGDOM.
authors.forename: Laurie-Anne
authors.initials: LA
authors.lastname: Marquet
authors.forename: Jeanick
authors.initials: J
authors.lastname: Brisswalter
authors.forename: Julien
authors.initials: J
authors.lastname: Louis
authors.forename: Eve
authors.initials: E
authors.lastname: Tiollier
authors.forename: Louise M
authors.initials: LM
authors.lastname: Burke
authors.forename: John A
authors.initials: JA
authors.lastname: Hawley
authors.forename: Christophe
authors.initials: C
authors.lastname: Hausswirth
mesh_terms: D000328:Adult; D056352:Athletes; D001642:Bicycling / Q000502:physiology; D001823:Body Composition; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D005080:Exercise Test; D005247:Feeding Behavior / Q000502:physiology*; D006801:Humans; D008297:Male; D062407:Meals; D010507:Periodicity; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology; D064133:Sports Nutritional Physiological Phenomena
chemical_list: D004040:Dietary Carbohydrates