his week, runners taking the 500 Mile and 400 Mile challenges begin running daily. Advanced athletes should add a 20–25-minute session (3 miles) of easy running on Monday, Wednesday, and Friday. Do these runs at the opposite time of day that you do your hard workout. Thursday: 1-mile warmup; 4 hill repeats (run 200 yds uphill, turn, jog downhill to start; repeat 3 times, no rests); 1-mile cool-down.