How long does it take to train for a marathon?
A full marathon is 42.2 km, and the training block itself usually runs 12 to 20 weeks. That assumes you already have a base: ideally you have run a half marathon, or at least run 25–30 km a week comfortably for a couple of months. Without that base, run a half marathon first.
| Your starting point | Recommended plan length | Notes |
|---|---|---|
| Run 10 km regularly, no half marathon yet | 20+ weeks | Do a half marathon plan first, then move into marathon training |
| Finished a half marathon | 16–20 weeks | Gradually build weekly distance and the long run |
| Run a marathon before | 12–16 weeks | Add marathon-pace work and a higher peak week |
| Experienced, chasing a time goal | 12–16 weeks | Threshold sessions, long runs with race-pace blocks |
The phases of a marathon plan
Most plans follow the same four phases. Knowing where you are in the cycle helps you understand why some weeks feel easy and others hard.
| Phase | Typical weeks | What you do |
|---|---|---|
| Base | First 4–6 | Mostly easy running, long run growing to 16–20 km, strides and strength |
| Build | Middle 4–6 | Weekly threshold or tempo session, marathon-pace segments, long run to 26–28 km |
| Peak | 2–3 weeks | Highest weekly distance, long run of 30–32 km, longest race-pace blocks |
| Taper | Final 2–3 | Volume down 20–40% each week, keep short race-pace efforts, rest |
Weekly distance and key sessions
| Level | Runs / week | Peak weekly distance | Peak long run |
|---|---|---|---|
| First marathon | 4 | 40–55 km | 30 km |
| Intermediate | 5 | 55–75 km | 30–32 km |
| Advanced | 5–6 | 75–100+ km | 32–35 km with race-pace segments |
- The long run is the centre of the week. Run most of it easy; later in the plan, finish some long runs with 5–10 km at goal marathon pace.
- Limit long runs to about 3 hours. Beyond that, the recovery cost outweighs the benefit for most runners, which is why plans peak around 30–32 km rather than the full distance.
- Threshold or tempo sessions, such as 2–3 × 10 minutes comfortably hard, raise the pace you can sustain.
- Easy runs make up most of the remaining distance. Keep them genuinely easy.
- Strength training twice a week through the base and build phases, reduced to once a week in the taper.
Marathon pace chart
Pick a goal time based on a recent half marathon: multiplying your half marathon time by about 2.1 gives a realistic marathon estimate for a well-trained runner, and more for a first marathon.
| Goal time | Pace per km | 10 km split | 21.1 km split | 30 km split |
|---|---|---|---|---|
| 3 h | 4:16 /km | 42:40 | 1:30:01 | 2:07:59 |
| 3 h 30 min | 4:59 /km | 49:46 | 1:45:01 | 2:29:18 |
| 4 h | 5:41 /km | 56:53 | 2:00:01 | 2:50:38 |
| 4 h 30 min | 6:24 /km | 1:03:59 | 2:15:01 | 3:11:58 |
| 5 h | 7:07 /km | 1:11:06 | 2:30:01 | 3:33:18 |
| 5 h 30 min | 7:49 /km | 1:18:12 | 2:45:01 | 3:54:37 |
| 6 h | 8:32 /km | 1:25:19 | 3:00:01 | 4:15:57 |
Fuelling: how to avoid hitting the wall
"Hitting the wall", usually somewhere after 30 km, happens when your stored carbohydrate runs low. Good fuelling delays or prevents it, and it has to be practised.
- During the race, aim for about 60–90 g of carbohydrate per hour, for example a gel every 25–40 minutes plus a sports drink. Train your gut by fuelling on every long run.
- Carb-load for 1–2 days before the race: make carbohydrate (rice, roti, potatoes, pasta, fruit) the main part of every meal while you rest. You do not need to eat much more food overall.
- Drink to thirst and use electrolytes. In humid races, sodium matters as much as water.
- Have a breakfast you have tested 2–3 hours before the start.
Marathon training in Indian conditions
- Season: most Indian marathons take place between October and February, so your long runs fall in the monsoon and early winter. Plan indoor or covered alternatives for heavy-rain days.
- Heat and humidity: do long runs at dawn and adjust pace for conditions. Coastal races stay humid even in winter, so practise drinking and taking electrolytes in the same conditions.
- Air quality: in North India from November to January, check the AQI before long runs and hard sessions. On "Poor" (201+) days, move quality work indoors or shorten it.
- Race start times: many races start between 4:30 and 6:30 am. Practise early-morning long runs, including breakfast, so your routine is familiar.
Taper and race day
Over the final 2–3 weeks, reduce weekly distance progressively (roughly 20–40% per week) while keeping short efforts at marathon pace. Feeling restless or sluggish during the taper is normal; it is not a sign of lost fitness.
On race day, run the first half at or slightly slower than goal pace. A negative or even split is the most reliable way to a good marathon; a fast first half is the most reliable way to a hard final 10 km.
General training information, not medical advice. Get a medical check-up before your first marathon, especially if you are over 40, have a heart condition or have not exercised regularly.