title: Energy balance during an ironman triathlon in male and female triathletes.
abstract: Energy balance of 10 male and 8 female triathletes participating in an Ironman event (3.8-km swim, 180-km cycle, 42.2-km run) was investigated. Energy intake (EI) was monitored at 7 designated points by dietary recall of food and fluid consumption. Energy expenditure (EE) during cycling and running was calculated using heart rate-VO, regression equations and during swimming by the multiple regression equation: Y = 3.65v+ 0.02W- 2.545 where Yis VO,in L x min(-1), v is the velocity in m s(-1), Wis the body weight in kilograms. Total EE (10,036 +/- 931 and 8,570 +/- 1,014 kcal) was significantly greater than total EI (3,940 +/- 868 and 3,115 +/- 914 kcal, p <.001) for males and females, respectively, although energy balance was not different between genders. Finishing time was inversely related to carbohydrate (CHO) intake (g x kg(-1) x h(-1)) during the marathon run for males (r = -.75,p <.05), and not females, suggesting that increasing CHO ingestion during the run may have been a useful strategy for improving Ironman performance in male triathletes.
authors: Department of Human Biology and Nutritional Sciences at the University of Guelph, ON, Canada.
authors: Nicholas E
authors: NE
authors: Kimber
authors: Jenny J
authors: JJ
authors: Ross
authors: Sue L
authors: SL
authors: Mason
authors: Dale B
authors: DB
authors: Speedy
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology; D001823:Body Composition; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D010101:Oxygen Consumption; D012420:Running / Q000502:physiology; D012727:Sex Characteristics; D012982:Sodium, Dietary / Q000008:administration & dosage; D013177:Sports / Q000502:physiology*; D013550:Swimming / Q000502:physiology
chemical_list: D004040:Dietary Carbohydrates; D012982:Sodium, Dietary