In the world of cycling, durability, also known as fatigue resistance, is the ability to resist fatigue throughout the duration of a ride or race.  It refers to the decay of physiological performance over time. In modern racing, the ability to produce high power outputs after several hours of riding is a key cycling ability. The winning moves are often made in the closing stages of an event, highlighting the importance of being able to perform well after prior work during tough races and challenges. Riders with better durability can sustain a higher percentage of their "fresh" state and typically achieve better results. 

Cycling durability in triathlons differs from road racing. Triathlon cycling typically involves a steadier intensity, and athletes must also prepare for the run that follows the bike leg. While professional triathletes encounter attacks and surges, these are generally less intense than in road races. Triathlons can be unpredictable, with athletes needing to navigate drafting rules and attempts to disrupt pace lines. This requires them to handle short bursts of high intensity, often at the beginning of the race, while still maintaining high relative power later on.