Stop running your easy days too hard and your hard days too easy. Tackling 26.2 miles requires safely building your aerobic engine without injury. Designed specifically for advanced runners looking to maximize their potential, this 24-week plan uses the proven 80/20 Endurance methodology. You will run 5 days a week, with 1 day of cross-training, introducing high-frequency, dual-intensity training. By adding a secondary, moderate threshold block each week, you will build extreme fatigue ...