Our Beginner Marathon Running Plan is 20 weeks. It is designed to safely increase your running volume to complete a marathon and enjoy the experience. Quick Overview: - Duration: 20 weeks - Runs per week: 4 - Key/Hard workouts per week: 1 - Cross-training days per week: 2 - Smart device structured workout compatible - Geared toward first time marathon runners Weekly mileage = 15-40 miles per week (weekday runs are based on duration so actual mileage may vary. Average weekly mileage is based ...