Running a sub-2 half marathon: pace, splits and the paces to train at
5:41 per kilometre, held for 21.1 km. Here is what that looks like at every mark, what it says about your fitness, and how to train for it.
Goal pace · half marathon
5:41 /km
9:09 /mi · 10.5 km/h on the treadmill · 2:00:00 at the finish
A sub-2 half marathon is 5:41 per kilometre, every kilometre, for 21.1 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-2 half marathon says your other race times should be, and the paces to train at to get there.
The splits for a sub-2 half 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 5 km at goal pace exactly, no faster. 5:41 will feel like a jog for the first twenty minutes. The runners passing you at 3 km are the runners you pass at 18 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 |
| Finish · 21.1 km | 6:15 | 2:00:00 |
What a sub-2 half marathon asks of you
The half is the distance where pacing stops being advice and becomes the result. It sits just under threshold for most runners, which means the first 10 km should feel almost easy and the last 5 km is where every second you banked early is repaid with interest. Even splits are not a style here; they are the fastest way to run it.
Where you need to be now
The fitness that runs a sub-2 half 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 36.5, which is the same engine as these:
| Distance | Riegel | VDOT | Pace |
|---|---|---|---|
| 5K | 26:05 | 26:04 | 5:13 /km |
| 10K | 54:23 | 54:07 | 5:26 /km |
| Half marathon · the goal | 2:00:00 | 2:00:00 | 5:41 /km |
| Marathon | 4:10:12 | 4:07:45 | 5:54 /km |
Read the 5K line first. If your current parkrun is slower than about 26:05, the sub-2 half 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-2 half 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 | 6:58 /km 11:13 /mi | Most of your week. Builds the aerobic base everything else sits on. |
| Threshold | 5:29 /km 8:50 /mi | Comfortably hard — roughly what you could hold for an hour. |
| Interval | 4:57 /km 7:58 /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-2 half marathon?
5:41 per kilometre, or 9:09 per mile, held evenly for the full 21.1 km. On a treadmill that is 10.5 km/h.
What 5K time do I need for a sub-2 half marathon?
About 26:05, 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 6:58 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.