Half marathon training plan: twelve weeks to 13.1 miles
This twelve-week plan builds from a comfortable 10K to the full 13.1 miles (21.1 kilometres). It uses four runs a week, a long run that grows to 11 or 12 miles, and a two-week taper.
Before you start
You should be able to run 10K, or for about an hour, without stopping, and be running three times a week. If that is still ahead of you, work through the 10K training plan first. See a GP before starting if you have a health condition or have been inactive.
How the week is arranged
There are four runs: two easy runs, one faster session and one long run. A typical layout is easy run on Tuesday, faster session on Thursday, easy run on Saturday and long run on Sunday, with Monday, Wednesday and Friday as rest days. Move the days to suit your life, but keep a rest day or an easy day either side of the faster session.
If four runs a week is too many, drop the second easy run. The long run and one other run are the two that matter most.
Understanding the sessions
- Easy: conversational pace. Most of your weekly distance is run like this.
- Intervals: efforts at roughly 10K pace with an easy jog between them. Start with ten minutes easy and finish with ten minutes easy.
- Tempo: a sustained effort that feels comfortably hard, about the pace you could hold for an hour. Warm up and cool down in the same way.
- Race pace: your target half marathon pace. The pace calculator converts a goal time into minutes per mile or kilometre.
- Long run: easy pace or slower, often 45 to 90 seconds per mile slower than race pace. The purpose is time on your feet.
The twelve-week plan
Distances are in miles, with kilometres in brackets for the long run.
| Week | Easy run | Faster session | Easy run | Long run |
|---|---|---|---|---|
| 1 | 3 mi | 4 x 2 min intervals, 2 min jog between | 3 mi | 4 mi (6.5 km) |
| 2 | 3 mi | 5 x 2 min intervals, 2 min jog between | 3 mi | 5 mi (8 km) |
| 3 | 3 mi | 4 x 3 min intervals, 2 min jog between | 4 mi | 6 mi (9.5 km) |
| 4 | 3 mi | Cutback: 3 mi easy with 4 x 20 sec strides | 3 mi | 5 mi (8 km) |
| 5 | 4 mi | 4 x 4 min intervals, 2 min jog between | 4 mi | 7 mi (11 km) |
| 6 | 4 mi | 15 min tempo | 4 mi | 8 mi (13 km) |
| 7 | 4 mi | 5 x 4 min intervals, 2 min jog between | 5 mi | 9 mi (14.5 km) |
| 8 | 4 mi | Cutback: 3 mi easy with 4 x 20 sec strides | 4 mi | 7 mi (11 km) |
| 9 | 4 mi | 20 min tempo | 5 mi | 10 mi (16 km) |
| 10 | 4 mi | 2 x 12 min tempo, 3 min jog between | 5 mi | 11 to 12 mi (18 to 19 km) |
| 11 | 4 mi | Taper: 3 x 5 min at race pace, 2 min jog between | 3 mi | 8 mi (13 km) |
| 12 | 3 mi | Taper: 2 mi easy with 4 x 1 min at race pace | Rest, or 2 mi very easy | Race day: 13.1 mi (21.1 km) |
Why the long run stops short of 13.1 miles
The longest training run is 11 or 12 miles, in week 10. You do not need to cover the full distance beforehand. With a taper behind you and other runners around you, the final mile or two is well within reach, and stopping short in training keeps recovery quick. Choose 11 miles if week 9 felt tough and 12 if it felt controlled.
Cutback weeks and the taper
Weeks 4 and 8 are lighter on purpose. They give your legs a chance to catch up before the next block of building. Weeks 11 and 12 are the taper: the long run drops to 8 miles, then the final week is very light. Resist the urge to add extra miles here. The tapering guide explains what to do and what to leave alone.
Practise for race day on long runs
From about week 6, use the long run as a rehearsal:
- Run at the time of day your event starts, having eaten the breakfast you plan to eat.
- Wear the shoes, socks and clothing you intend to race in. The race day kit page has suggestions.
- On runs over 75 to 90 minutes, practise drinking and, if you plan to use them, taking gels or other food.
- Finish the last mile or two of an occasional long run at race pace.
Missed training
If you miss a week, repeat the previous one. If you miss two, go back two weeks and accept a shorter longest run: reaching 10 miles in training is enough to finish. Never skip the taper to catch up.
Setting a goal
A recent 10K time is the best guide to what you can run. Enter it into the race time predictor for an estimate, and write your target mile splits on your hand or a wristband to keep the early miles under control. The half marathon guide describes how the distance unfolds on the day.