Our Intermediate Half Marathon Running Plan is 12 weeks. It is designed to help runners transition from a 10K or improve their previous half marathon time. Quick Overview: - Duration: 12 weeks - Runs per week: 4 - Key/Hard workouts per week: 2 - Cross-training days per week: 2 - Smart device structured workout compatible - Geared toward runners stepping up from 5K/10K running and runners that have done half marathons but not completed many speed/tempo workouts in the past. Weekly mileage = ...