Ultra-endurance is defined as any exercise that lasts longer than 8-12 hours. Generally, expeditions and adventure racing fall under this category, in particular events lasting multiple days. Ultra-endurance exercise demands exceptional mental resilience and depends almost entirely upon aerobic metabolism which ranges from 70% (I) to 99% (IV). Ultra-endurance athletes can do long-lasting aerobic exercise more efficiently and at a relatively high intensity. Occasionally, short intensity bursts may occur during ultra-endurance exercise. The transition from ultra-endurance to expeditionlike events is smooth and may vary between and even within events, depending, for example, on weather conditions, particularly during multi-day events.
Needless to say, energy supply is a major factor limiting performance. Often, replenishments aren’t available and must be brought along. Nutritional requirements depend on the circumstances such as duration, sleep and climate. Often, non-perishable energy dense foods that can be easily transported and withstand both low and high temperatures are preferred. The tolerance to foods and palatability on the other hand are of minor concern.
