title: Voluntary food intake by elite female cyclists during training and racing: influence of daily energy expenditure and body composition.
abstract: We estimated self-reported energy intake (EI) and cycling energy expenditure (CEE) during racing and training over 26 days (9 days recovery [REC], 9 days training [TRN], and 8 days racing [RACE], which included a 5-day stage race) for 8 members of the Australian National Training Squad [mean SD; 25.1 4.0 years, 59.2 4.4 kg, 3.74 0.24 L min-1 VO 2 peak, 13.6 4.5 % Body fat (% B fat)]. After 70 days of training and racing, average body mass increased by 1.1 kg (95%CI 0.5 to 1.7 kg; p <.01) and average % B fat decreased by 0.9% (95%CI 1.7 to 0.1%; p <.05). These minor changes, however, were not considered clinically significant. CEE was different between RACE, TRN, and REC (2.15 0.18 vs. 1.73 0.25 vs. 0.72 0.15 MJ d-1, p <.05). Reported EI for RACE and TRN were higher than REC (14.87 3.03, 13.70 4.04 vs. 11.98 3.57 MJ d-1, p <.05). Reported intake of carbohydrate for RACE and TRN were also higher than REC (588 122, 536 130 vs. 448 138 g d-1, p <.05). Reported intake of fat (59 21 68 21 g d-1) was similar during RACE, TRN, and REC, whereas protein intake tended to be higher during TRN (158 49 g d-1) compared to RACE and REC (136 33; 130 33 g d-1). There was a relationship between average CEE and average EI over the 26 days (r = 0.77, p <.05), but correlations between CEE and EI for each of the women varied (r = 0.02 to 0.67). There was a strong trend for an inverse relationship between average EI and % Bf at (r = -.68, p =.06, n = 8). In this study, increases in reported EI during heavy training and racing were the result of an increase in carbohydrate intake. Most but not all cyclists modulated EI based on CEE. Research is required to determine whether physiological or psychological factors are primarily responsible for the observed relationship between CEE and EI and also the inverse correlation between % B fat and EI.
authors.affiliation: School of Health Sciences, Deakin Univesrity, Burwood Victoria, Australia.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Martin
authors.forename: David T
authors.initials: DT
authors.lastname: Martin
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Collier
authors.forename: Louise M
authors.initials: LM
authors.lastname: Burke
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D004435:Eating / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D010807:Physical Endurance / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D012650:Self Disclosure
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins