Energy, macronutrient and water intake during a mountain ultramarathon event: The influence of distance

Most participants in mountain ultramarathon events consume insufficient carbohydrates, with less than half meeting recommended intakes of 30 g per hour. A study analyzing the 'Ultra Mallorca Serra de Tramuntana' event found that while average energy intake was stable across marathon (44 km), trail (67 km), and ultra (112 km) distances—at approximately 183 kcal/hour—a significant portion of runners, particularly in longer races, relied more on lipids for energy. Water intake also varied by distance, with the longest race showing the lowest hourly consumption despite adequate overall hydration. Surprisingly, race length did not significantly alter nutritional strategies, suggesting that endurance performance may not strictly depend on distance-specific fueling patterns.

Martinez, S., Aguilo, A., Rodas, L., Lozano, L., Moreno, C., & Tauler, P. (2017). Energy, macronutrient and water intake during a mountain ultramarathon event: The influence of distance. Journal of Sports Sciences, 36(3), 333–339. https://doi.org/10.1080/02640414.2017.1306092