Anecdotal claims have suggested that an increasing number of ultramarathoners purposely undertake chronic low-carbohydrate (CHO) ketogenic diets while training, and race with very low CHO intakes, as a way to maximize fat oxidation and improve performance. However, very little empirical evidence exists on specific fueling strategies that elite ultramarathoners undertake to maximize race performance. The study’s purpose was to characterize race nutrition habits of elite ultramarathon runners. Three veteran male ultrarunners (M ± SD; age 35 ± 2 years; mass 59.5 ± 1.7 kg; 16.7 ± 2.5 hr 100-mi. best times) agreed to complete a competition-specific nutrition intake questionnaire for 100-mi. races. Verbal and visual instructions were used to instruct the athletes on portion sizes and confirm dietary intake. Throughout 2014, the athletes competed in 16 ultramarathons with a total of 8 wins, including the prestigious Western States Endurance Run 100-miler (14.9 hr). The average prerace breakfast contained 70 ± 16 g CHO, 29 ± 20 g protein, and 21 ± 8 g fat. Athletes consumed an average of 1,162 ± 250 g of CHO (71 ± 20g/hr), with minor fat and protein intakes, resulting in caloric intakes totaling 5,530 ± 1,673 kcals (333 ± 105 kcals/hr) with 93% of calories coming from commercial products. Athletes also reported consuming 912 ± 322 mg of caffeine and 6.9 ± 2.4 g of sodium. Despite having limited professional nutritional input into their fueling approaches, all athletes practiced fueling strategies that maximize CHO intake and are congruent with contemporary evidence-based recommendations.
Stellingwerff is with the Canadian Sports Institute Pacific, Victoria, British Columbia, Canada.