The Prismy Problem: Why Speed Endurance Fails and How to Fix It
Speed endurance is the ability to sustain high power or pace when fatigue is screaming at you to slow down. It's what separates a runner who fades in the last 800 meters from one who surges past the competition. Yet, despite its importance, most training plans fail to develop it effectively. The problem isn't a lack of effort — it's a lack of clarity. Athletes and coaches often confuse speed endurance with pure speed or aerobic endurance, leading to workouts that miss the mark. In this guide, we break down the real reasons speed endurance fails and give you a practical framework to fix it. Who Must Choose and by When Every endurance athlete faces a decision point: how to allocate training time to build speed endurance without sacrificing other qualities. This choice is most critical during the 8–12 weeks before a target race.