title: A scientific nutrition strategy improves time trial performance by ≈6% when compared with a self-chosen nutrition strategy in trained cyclists: a randomized cross-over study.
abstract: We investigated whether an athlete's self-chosen nutrition strategy (A), compared with a scientifically determined one (S), led to an improved endurance performance in a laboratory time trial after an endurance exercise. S consisted of about 1000 mL·h(-1) fluid, in portions of 250 mL every 15 min, 0.5 g sodium·L(-1), 60 g glucose·h(-1), 30 g fructose·h(-1), and 5 mg caffeine·kg body mass(-1). Eighteen endurance-trained cyclists (16 male; 2 female) were tested using a randomized crossover-design at intervals of 2 weeks, following either A or S. After a warm-up, a maximal oxygen uptake test was performed. Following a 30-min break, a 2.5-h endurance exercise on a bicycle ergometer was carried out at 70% maximal oxygen uptake. After 5 min of rest, a time trial of 64.37 km (40 miles) was completed. The ingested nutrition was recorded every 15 min. In S, the athletes completed the time trial faster (128 vs. 136 min; p ≤ 0.001) and with a significantly higher power output (212 vs. 184 W; p ≤ 0.001). The intake of fluid, energy (carbohydrate-, mono-, and disaccharide), and sodium was significantly higher in S compared with A (p ≤ 0.001) during the endurance exercise. In the time trial, only sodium intake was significantly higher in S (p ≤ 0.001). We concluded that a time trial performance after a 2.5-h endurance exercise in a laboratory setting was significantly improved following a scientific nutrition strategy.
authors.affiliation: Department of Sport Science, Martin-Luther University Halle-Wittenberg, Von-Seckendorff-Platz 2, 06120 Halle, Germany. kuno.hottenrott@sport.uni-halle.de
authors.forename: Kuno
authors.initials: K
authors.lastname: Hottenrott
authors.forename: Erik
authors.initials: E
authors.lastname: Hass
authors.forename: Manon
authors.initials: M
authors.lastname: Kraus
authors.forename: Georg
authors.initials: G
authors.lastname: Neumann
authors.forename: Martin
authors.initials: M
authors.lastname: Steiner
authors.forename: Beat
authors.initials: B
authors.lastname: Knechtle
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001628:Beverages; D001642:Bicycling / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D019587:Dietary Supplements; D004326:Drinking / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D052756:Nutritional Sciences; D010807:Physical Endurance / Q000502:physiology*; D012648:Self Care / Q000379:methods*; D014882:Water-Electrolyte Balance / Q000502:physiology
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D019344:Lactic Acid