title: Perturbed energy balance and hydration status in ultra-endurance runners during a 24 h ultra-marathon.
abstract: The present study aimed to assess the adequacy of energy, macronutrients and water intakes of ultra-endurance runners (UER) competing in a 24 h ultra-marathon (distance range: 122-208 km). The ad libitum food and fluid intakes of the UER (n 25) were recorded throughout the competition and analysed using dietary analysis software. Body mass (BM), urinary ketone presence, plasma osmolality (POsmol) and volume change were determined at pre- and post-competition time points. Data were analysed using appropriate t tests, with significance set at P <0·05. The total energy intake and expenditure of the UER were 20 (sd 12) and 55 (sd 11) MJ, respectively (control (CON) (n 17): 12 (sd 1) and 14 (sd 5) MJ, respectively). The protein, carbohydrate and fat intakes of the UER were 1·1 (sd 0·4), 11·3 (sd 7·0) and 1·5 (sd 0·7) g/kg BM, respectively. The rate of carbohydrate intake during the competition was 37 (sd 24) g/h. The total water intake of the UER was 9·1 (sd 4·0) litres (CON: 2·1 (sd 1·0) litres), while the rate of water intake was 378 (sd 164) ml/h. Significant BM loss occurred at pre- to post-competition time points (P =0·001) in the UER (1·6 (sd 2·0) %). No significant changes in POsmol values were observed at pre- (285 (sd 11) mOsmol/kg) to post-competition (287 (sd 10) mOsmol/kg) time points in the UER and were lower than those recorded in the CON group (P <0·05). However, plasma volume (PV) increased at post-competition time points in the UER (10·2 (sd 9·7) %; P <0·001). Urinary ketones were evident in the post-competition samples of 90 % of the UER. Energy deficit was observed in all the UER, with only one UER achieving the benchmark recommendations for carbohydrate intake during endurance exercise. Despite the relatively low water intake rates recorded in the UER, hypohydration does not appear to be an issue, considering increases in PV values observed in the majority (80 %) of the UER. Population-specific dietary recommendations may be beneficial and warranted.
authors.affiliation: Department of Nutrition and Dietetics,Monash University,Level 1, 264 Ferntree Gully Road,Notting Hill, Victoria3168,Australia.
authors.forename: Ricardo J S
authors.initials: RJ
authors.lastname: Costa
authors.affiliation: Sport and Exercise Science Applied Research Group, Coventry University,Priory Street,Coventry,CV1 5FB,UK.
authors.forename: Samantha K
authors.initials: SK
authors.lastname: Gill
authors.affiliation: Sport and Exercise Science Applied Research Group, Coventry University,Priory Street,Coventry,CV1 5FB,UK.
authors.forename: Joanne
authors.initials: J
authors.lastname: Hankey
authors.affiliation: Sport and Exercise Science Applied Research Group, Coventry University,Priory Street,Coventry,CV1 5FB,UK.
authors.forename: Alice
authors.initials: A
authors.lastname: Wright
authors.affiliation: Sport and Exercise Science Applied Research Group, Coventry University,Priory Street,Coventry,CV1 5FB,UK.
authors.forename: Slawomir
authors.initials: S
authors.lastname: Marczak
mesh_terms: D000328:Adult; D001834:Body Water; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D004326:Drinking; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D010807:Physical Endurance / Q000502:physiology*; D010953:Plasma Volume; D012420:Running / Q000502:physiology*
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins