How many weeks do you need to train for each distance?
Short answer
From a base of running a few times a week, allow about 6–8 weeks for a 5K, 8–10 for a 10K, 10–14 for a half marathon and 16–20 for a marathon. Starting from scratch, add several weeks.
Key points
- The time assumes you already run a few times a week.
- Starting from scratch? Add four to eight weeks, more for longer races.
- Too little time means a gentler goal, not a harder plan.
Typical build-ups
| Distance | From a running base | From scratch |
|---|---|---|
| 5K | 6–8 weeks | 9–12 weeks |
| 10K | 8–10 weeks | 12–16 weeks |
| Half marathon | 10–14 weeks | 16–20 weeks |
| Marathon | 16–20 weeks | 6 months or more |
The NHS Couch to 5K programme, for example, takes absolute beginners to running 5K in nine weeks, running three times a week.
Why it takes this long
Your heart and lungs respond within weeks, but tendons, bones and joints adapt more slowly. Weekly running has to grow gradually, and the last week or two before the race are lighter on purpose: the taper.
If your race is soon
You can still train for it. The plan builds more cautiously, keeps the long run within reach, and may suggest treating it as a run to enjoy rather than one to race flat out.
In your plan
Your plan runs from today to race day. If the weeks you have are short for the distance and your level, the plan's summary says so and the training builds more gently.
Related questions
5K, 10K, half or marathon: which should I train for first?
Pick the distance you can train for safely in the weeks you have. For most people starting out that is a 5K or 10K; a half or full marathon makes sense once you already run several times a week.
Read the full answerWhat is a taper?
A taper is the last part of training before a race, when you run noticeably less but keep some faster running, so you arrive rested rather than tired.
Read the full answerHow do I pick a realistic finish time?
Start from a recent race or timed run and scale it to the new distance. With no recent time, leave a rough guess or make finishing comfortably your goal; your plan will tell you how realistic it looks.
Read the full answerThanks. That helps us improve this answer.