Stop running your easy days too hard and your hard days too easy. Targeted at intermediate runners looking to improve their half-marathon time significantly, this 20-week plan introduces a critical 5th day of running impact to build structural resilience and expand VO2 Max-specific pacing. It also transitions your weekend efforts into Endurance Fast Finishes (EFF) to teach your body to hold a strong pace under heavy aerobic fatigue, a key component for half-marathon mastery. What It Delivers: ...