The 80/20 Rule in Endurance Sports: A Personal Journey to Peak Performance Endurance sports are a test of will, stamina, and strategy. But even the most dedicated athletes can fall into the trap of overtraining, leading to injuries and burnout. That’s where the 80/20 rule, a principle grounded in decades of research and observation, comes into play. It’s a strategy that has transformed not only my training but also my overall performance and well-being.