This 20-week marathon 2.1 intermediate training plan prepares for a marathon in under 3:45 hours with 4 running days/week. Training starts at 42 km/week and peaks at 64 km/week. For each run, I provide the exact pace range. Simply set up your training zones based on your fitness level with a click of a mouse button. • Upload all workouts to your running watch • Switch plan level, free within 14 days • Free email coach support