Race Shape › Answers › How long does it take to train for a marathon?
AnswersHow long does it take to train for a marathon?
About 16 to 20 weeks for a runner who already runs regularly, and longer for a first marathon. That allows a base phase, a build, a peak and a three-week taper. Six weeks or fewer is not enough to add meaningful aerobic fitness — at that point a plan can keep you healthy and get the pacing right, but not make you much fitter.
By starting point
| Where you are now | Sensible block |
|---|---|
| Running 40 km+ a week, has raced a half | 16 weeks |
| Running 25–40 km a week | 18–20 weeks |
| New to running, or under 20 km a week | 20+ weeks — or a half marathon first |
| Six weeks or less | Not enough to add fitness; arrive healthy and pace conservatively |
What the weeks are for
| Phase | Purpose |
|---|---|
| Base | Mostly easy running, building volume and the long run |
| Build | Threshold and race-pace sessions arrive |
| Peak | The biggest, most race-specific weeks |
| Taper | Three weeks: volume falls, intensity stays |
The single most reliable predictor of a good marathon is weeks of consistent running before it. A 20-week block done steadily beats a 12-week block done heroically.
Common questions
Can I train for a marathon in 12 weeks?
Yes, if you already run regularly and have a half marathon or similar in your legs. From a low base, 12 weeks is short.
How many days a week?
Four to six. Four is enough to finish well; more days mostly spread the same volume more gently.
What is the longest run?
Race Shape caps it at 34 km, and at about 35% of the week.
Sources
- Daniels, J. Daniels' Running Formula.
- Bosquet, L. et al. (2007). Effects of tapering on performance: a meta-analysis. Medicine & Science in Sports & Exercise.