As with many of my answers...it depends. Generally, plans can range from 12-30 weeks depending upon race goals, experience, age, life schedule, base mileage, and injury history. For example, runners age 40+ or those with a history of injuries need to factor in more time for recovery. Runners with hectic, stressful lives need to factor in more time to allow for missing runs. While those who are frequent racers, properly recover, maintain base mileage and fitness between races, can train in less time.
Recommended Base Mileage for Goal Pace Oriented Runners Prior to Commencing Training
- Half: min base mileage 12 miles/week with a long run up to 4 miles
- Full: min base mileage 22-24 miles/per week with a long run up to 10 miles.
Goal pace oriented runners with experience and proper base mileage should consider 16/20 weeks, half/full marathon respectively, for a plan that takes into account recovery weekends and potential illnesses and other setbacks.
Novice runners with less base mileage should consider 24/28 weeks, half/full marathon respectively, for a plan that takes into account recovery weekends and potential illnesses and other setbacks.
True Couch Potatoes (inactive, no run experience) should consider a conservative walk/jog program of 6 mo. to safely prepare for a 5K. Training and racing 5K's and 10K's for a year is recommended before considering longer distances. Cardio fitness comes quickly but muscles and tendons take years to adapt to running.