Running a sub-4 marathon: pace, splits and the paces to train at
5:41 per kilometre, held for 42.2 km. Here is what that looks like at every mark, what it says about your fitness, and how to train for it.
Goal pace · marathon
5:41 /km
9:09 /mi · 10.5 km/h on the treadmill · 4:00:00 at the finish
A sub-4 marathon is 5:41 per kilometre, every kilometre, for 42.2 km. That is 9:09 per mile, or 10.5 km/h if you are dialling it into a treadmill. Below are the splits you need to pass each mark on, what a sub-4 marathon says your other race times should be, and the paces to train at to get there.
The splits for a sub-4 marathon
Even splits. Not because they look tidy, but because an even-paced race is the fastest way most runners can cover a distance, and a fast first half is the most common way a goal time is lost. Run the first 10 km at goal pace or a few seconds slower. 5:41 is the fastest you should see on your watch before halfway, and a 5 km split under it in the first half is a mistake you will meet again at 35 km.
| Mark | Split | Elapsed |
|---|---|---|
| 5 km | 28:26 | 28:26 |
| 10 km | 28:26 | 56:53 |
| 15 km | 28:26 | 1:25:19 |
| 20 km | 28:26 | 1:53:45 |
| 25 km | 28:26 | 2:22:12 |
| 30 km | 28:26 | 2:50:38 |
| 35 km | 28:26 | 3:19:05 |
| 40 km | 28:26 | 3:47:31 |
| Finish · 42.2 km | 12:29 | 4:00:00 |
What a sub-4 marathon asks of you
A marathon goal time is a promise your long runs have to keep. The pace itself is well below threshold for most runners; what breaks a marathon is not the pace at 10 km but whether the legs have been taught to hold it at 35 km. That is why a marathon target is a training question before it is a race-day one.
Where you need to be now
The fitness that runs a sub-4 marathon shows up at every other distance. The two models coaches use — Riegel's formula and the Daniels & Gilbert VDOT tables — put it at a VDOT of about 37.9, which is the same engine as these:
| Distance | Riegel | VDOT | Pace |
|---|---|---|---|
| 5K | 25:01 | 25:14 | 5:01 /km |
| 10K | 52:10 | 52:22 | 5:14 /km |
| Half marathon | 1:55:07 | 1:56:06 | 5:29 /km |
| Marathon · the goal | 4:00:00 | 4:00:00 | 5:41 /km |
Read the 5K line first. If your current parkrun is slower than about 25:07, the sub-4 marathon is a fitness goal before it is a pacing goal, and the gap in that number is the gap your training has to close. The goal time calculator scores how likely that is against the weeks you have; the race time predictor runs the same projection from any recent race.
Equivalent times assume you are equally trained for every distance. Nobody is. The further the distance from the one you race most, the more these drift — and over the marathon both models are optimistic for anyone who has not done the long runs.
The paces to train at
A sub-4 marathon is not trained at 5:41. It is trained mostly well below it and occasionally above it. These are the three paces the VDOT model prescribes for this fitness; the easy one is the one most runners get wrong, and they get it wrong by running it too fast.
| Effort | Pace | What it is for |
|---|---|---|
| Easy | 6:46 /km 10:53 /mi | Most of your week. Builds the aerobic base everything else sits on. |
| Threshold | 5:19 /km 8:33 /mi | Comfortably hard — roughly what you could hold for an hour. |
| Interval | 4:48 /km 7:43 /mi | The pace that raises your ceiling. Reps of 3–5 minutes. |
Easy pace builds the base everything else sits on and should feel almost too slow. Threshold is the comfortably hard pace you could hold for about an hour, the single most useful session for anything 10K and up. Interval pace raises the ceiling in reps of three to five minutes. A training plan is the arrangement of those three across a week, with the long run growing underneath them — which is what the Outrunr app builds from one honest race time, and re-prices every time you run.
Running pace calculator · parkrun time calculator · What your parkrun time means
Common questions
What pace is a sub-4 marathon?
5:41 per kilometre, or 9:09 per mile, held evenly for the full 42.2 km. On a treadmill that is 10.5 km/h.
What 5K time do I need for a sub-4 marathon?
About 25:07, by the average of the Riegel and VDOT models. That is the aerobic fitness the goal asks for; the longer the goal distance, the more it also asks for long-run endurance a 5K cannot measure.
Should I run even splits?
Yes. For most runners an even-paced race is the fastest way to cover the distance, with the second half a touch quicker if anything. A fast first half is the most common way a goal time is lost.
What should my easy runs be at?
Well slower than 5:41. For this fitness the VDOT model puts easy pace around 6:46 per km. If that feels too slow, that is the point: it is the pace that lets you absorb the hard sessions.
parkrun® is a registered trade mark of parkrun Limited. Outrunr is not affiliated with or endorsed by parkrun. VDOT is a trade mark of its owner. Outrunr implements the published Daniels & Gilbert formula and is not affiliated with them.