20-Week Marathon Training Plan

Free 20-week marathon training plan for beginners and intermediate runners. Build from base to race day with a complete periodized schedule.

Twenty weeks gives you the most complete marathon preparation: a full base-building phase, structured tempo and interval development, sharpening, and taper. The right choice for first-timers and runners targeting a PR.

20 weeks from base building to taper
Conservative mileage progression to prevent injury
Best for first marathons and PR attempts
Export full schedule to Google or Apple Calendar

How to follow a 20-week marathon training plan

Build a complete 20-week marathon training schedule from base to race day

Select Marathon: Choose Marathon as your goal race distance
Set race date 20 weeks out: Enter a race date at least 20 weeks from today
Choose your level: Beginner for first marathon, Intermediate for PR attempts
Generate and export: Get your plan and export to calendar for daily workout reminders

Frequently asked questions

Who should use a 20-week marathon training plan?

A 20-week plan is ideal for first-time marathoners, runners returning from a break, and those targeting a significant PR. The extended base phase builds the aerobic foundation that makes speed work in later phases more effective.

How does a 20-week marathon plan differ from a 16-week plan?

The primary difference is the base-building phase. A 20-week plan has 6–8 weeks of easy aerobic base running before structured quality sessions begin. A 16-week plan compresses this phase and assumes more existing mileage. Both plans peak at the same long run distance.

Plan length and phase structure

Plan length and phase split by race and fitness level (weeks)
Race	Level	Total	Base	Development	Sharpening	Taper
5K	Beginner	8	2	2	2	1
5K	Intermediate	10	3	2	3	1
5K	Advanced	12	4	3	3	1
10K	Beginner	10	3	2	3	1
10K	Intermediate	12	4	3	3	1
10K	Advanced	14	5	4	3	1
Half Marathon	Beginner	12	4	3	2	2
Half Marathon	Intermediate	14	4	3	4	2
Half Marathon	Advanced	16	5	4	4	2
Marathon	Beginner	16	5	4	4	2
Marathon	Intermediate	18	6	5	4	2
Marathon	Advanced	20	7	5	5	2

Method and sources

The numbers on this page are computed with the same code as the TrainPace calculators, from these published methods. They are training guidance, not medical advice.

Daniels, J. Daniels' Running Formula. Human Kinetics — VDOT, training zones, and equivalent race times.
Daniels, J. & Gilbert, J. (1979). Oxygen Power: Performance Tables for Distance Runners — the oxygen-cost and %VO2max equations behind VDOT.

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