Endurance is the ability to sustain physical activity for an extended period without succumbing to fatigue. In sports, endurance is a critical factor for success, especially in disciplines that require prolonged exertion, such as long-distance running, cycling, swimming, and rowing. While many athletes focus on speed and strength, endurance plays a fundamental role in determining overall performance and efficiency.

There are two primary types of endurance: aerobic and anaerobic. Aerobic endurance refers to the ability of the cardiovascular system to supply oxygen to muscles over an extended period. This is vital for sports where sustained, moderate-intensity efforts are required. Activities such as marathons or triathlons demand superior aerobic capacity. On the other hand, anaerobic endurance is associated with high-intensity efforts that are of shorter duration, relying on energy systems that do not require oxygen. This type of endurance is essential for sports that involve bursts of intense effort, such as sprinting or weightlifting.

The role of genetics in endurance is often debated, as it plays a significant part in an athlete's ability to develop stamina. Studies have shown that some individuals are naturally predisposed to better endurance due to factors such as muscle fiber composition and cardiovascular efficiency. These genetic traits may give some athletes an advantage, but training and lifestyle choices remain pivotal in enhancing endurance.