NUTRITIONAL AND FLUID INTAKE IN A 100-KM ULTRAMARATHON

The fluid and food Intakes of 7 male participants in a 100-km ultramar athon were recorded. The mean exercise time was 10 hr 29 min. Nutrient analysis revealed a mean intrarace energy intake of 4,233 kJ, with 88 .6% derived from carbohydrate, 6.7% from fat, and 4.7% from protein. F luid intake varied widely, 3.3-11.1 L, with a mean of 5.7 L. The mean decrease in plasma volume at 100 km was 7.3%, accompanied by an estima ted mean sweat rate of 0.86 L.hr(-1). Blood glucose concentrations rem ained normal during the event, and free fatty acids and glycerol were elevated both during and at the conclusion of the event. No significan t correlations were found between absolute amounts and rates of ingest ion of carbohydrate and/or fluid and race performance.