The fluid and food intakes of 7 male participants in a 100-km ultramarathon were recorded. The mean exercise time was 10 hr 29 min. Nutrient analysis revealed a mean inlrarace energy intake of 4.233 kJ. with 88.6% derived from carbohydrate. 6.7% from fat, and 4.7% from protein. Fluid intake varied widely. 3.3–1 1.1 L, with a mean of 5.7 L. The mean decrease in plasma volume at 100 km was 7.3%, accompanied by an estimated mean sweat rale of 0.86 L ⋅ hr−1. Blood glucose concentrations remained normal during the event, and free fatty acids and glycerol were elevated both during and at the conclusion of the event. No significant correlations were found between absolute amounts and rates of ingestion of carbohydrate and/or fluid and race performance.
K.E. Fallon is with the Department of Sports Medicine, and E. Broad is with the Department of Sports Nutrition, Australian Institute of Sport, Canberra. Australia. M.W. Thompson and P.A. Reull are with the Department of Biomedical Sciences. The University of Sydney, Sydney. Australia. Direct correspondence to Kieran Fallon, Department of Sports Medicine, Australian Institute of Sport, PO Box 176 Belconnen, Australia 2616.