I just got recertified as a UESCA Ultrarunning Coach. As part of the recertification process, I wrote and submitted a paper titled Durability in Endurance Exercise: Concept, History, and Applications for Trail Running.
DurabilityDurability refers to the time course and magnitude of deterioration in an athlete’s physiological, mechanical, and performance-related characteristics… More is a key performance factor in ultra-endurance events. It describes how an athlete’s physiological functions deteriorate over time during prolonged exercise—how well performance is maintained as fatigue accumulates.
In practical terms, durability reflects an athlete’s ability to stay strong deep into long events, such as ultra-trail races, where hours of climbing, descending, and environmental factors like heat or extreme cold, along with nutrition challenges, gradually wear the body down.
I’ve long considered durability a crucial element of trail running. As a coach, I apply training approaches such as multi-day camps and specialized workouts to help my runners become more durable.

Do you want to dive deeper into the concept of durability? Check out the paper here.
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