Training plan · 12 weeks · km and miles
12-week half marathon training plan
A 12-week half marathon plan in two versions: beginner, with 4 runs a week building from 20 km (12 mi) to 35 km (22 mi), and intermediate, with 5 runs a week from 34 km (21 mi) to 55 km (34 mi). Every week has one key session and a weekend long run, weeks 4 and 8 are recovery weeks, and the last 2 weeks taper to race day.
From textfit.app/plans/12-week-half-marathon-training-plan/
The plan at a glance
| Beginner | Intermediate | |
|---|---|---|
| Length | 12 weeks | 12 weeks |
| Runs a week | 4: 1 key session, 1 long run, 2 easy | 5: 1 key session, 1 long run, 3 easy |
| Weekly distance | 20 km (12 mi) → 35 km (22 mi) in week 10 | 34 km (21 mi) → 55 km (34 mi) in week 10 |
| Long run | 8 km (5 mi) → 16 km (10 mi) in week 10 | 12 km (7 mi) → 20 km (12 mi) in week 10 |
| Recovery weeks | Weeks 4 and 8 | Weeks 4 and 8 |
| Phases | Base (weeks 1–4) → Build (weeks 5–8) → Peak (weeks 9–10) → Taper (weeks 11–12) | |
The rules behind every week
- Weekly distance rises by 10% or less from one week to the next.
- Every 4th week is a recovery week with 30–40% less distance than the week before.
- Two hard days a week at most, never back to back: the key session on Tuesday and the long run on Sunday.
- About 80% easy: the hard part of every training week stays under 20% of its distance.
- The long run is on the weekend and mostly easy; at most a quarter of it at race pace.
- A 2-week taper brings the distance down before race day.
These are the rules TextFit’s coach plans with, and a test checks every week of the tables below against them. More on the rules: how the coach builds and adapts a week.
Beginner plan: 12 weeks, 4 runs a week
Tuesday key session, easy runs on Thursday and Saturday, long run on Sunday. Monday, Wednesday and Friday are rest days.
Before week 1
- You run 3 times a week, about 15–20 km (10–12 mi) in total, and have done for at least 2 months.
- You can run 8 km (5 mi) without stopping, at a pace where you could still talk.
- You have about an hour on two weekdays and up to 2 hours on Sunday.
| Week | Mon | Tue | Wed | Thu | Fri | Sat | Sun | Total |
|---|---|---|---|---|---|---|---|---|
| 1 Base | Rest | Fartlek 5 km (3.1 mi) 6×200 m @ brisk effort, 200 m jogs | Rest | Easy 4 km (2.5 mi) | Rest | Easy 3 km (1.9 mi) | Long run 8 km (5 mi) | 20 km 12.4 mi |
| 2 Base | Rest | Hills 5 km (3.1 mi) 6×200 m uphill, jog down | Rest | Easy 5 km (3.1 mi) | Rest | Easy 3 km (1.9 mi) | Long run 9 km (5.6 mi) | 22 km 13.7 mi |
| 3 Base | Rest | Fartlek 6 km (3.7 mi) 8×200 m @ brisk effort, 200 m jogs | Rest | Easy 5 km (3.1 mi) | Rest | Easy 3 km (1.9 mi) | Long run 10 km (6.2 mi) | 24 km 14.9 mi |
| 4 Base Recovery | Rest | Fartlek 4 km (2.5 mi) 4×200 m @ brisk effort, 200 m jogs | Rest | Easy 3 km (1.9 mi) | Rest | Easy 3 km (1.9 mi) | Long run 6 km (3.7 mi) | 16 km 9.9 mi |
| 5 Build | Rest | Threshold 7 km (4.3 mi) 3×1 km @ threshold, 400 m jogs | Rest | Easy 5 km (3.1 mi) | Rest | Easy 3 km (1.9 mi) | Long run 11 km (6.8 mi) | 26 km 16.2 mi |
| 6 Build | Rest | Intervals 7 km (4.3 mi) 4×800 m @ interval pace, 400 m jogs | Rest | Easy 5 km (3.1 mi) | Rest | Easy 4 km (2.5 mi) | Long run 12 km (7.5 mi) | 28 km 17.4 mi |
| 7 Build | Rest | Tempo 7 km (4.3 mi) 3 km @ tempo | Rest | Easy 6 km (3.7 mi) | Rest | Easy 4 km (2.5 mi) | Long run 13 km (8.1 mi) | 30 km 18.6 mi |
| 8 Build Recovery | Rest | Threshold 5 km (3.1 mi) 2×1 km @ threshold, 400 m jogs | Rest | Easy 4 km (2.5 mi) | Rest | Easy 3 km (1.9 mi) | Long run 8 km (5 mi) | 20 km 12.4 mi |
| 9 Peak | Rest | Threshold 8 km (5 mi) 4×1 km @ threshold, 400 m jogs | Rest | Easy 6 km (3.7 mi) | Rest | Easy 4 km (2.5 mi) | Long run 14 km (8.7 mi) last 2 km @ steady | 32 km 19.9 mi |
| 10 Peak | Rest | Half marathon pace 8 km (5 mi) 2×2 km @ half marathon pace, 400 m jogs | Rest | Easy 6 km (3.7 mi) | Rest | Easy 5 km (3.1 mi) | Long run 16 km (9.9 mi) last 2 km @ half marathon pace | 35 km 21.7 mi |
| 11 Taper | Rest | Threshold 7 km (4.3 mi) 3×1 km @ threshold, 400 m jogs | Rest | Easy 5 km (3.1 mi) | Rest | Easy 4 km (2.5 mi) | Long run 12 km (7.5 mi) | 28 km 17.4 mi |
| 12 Taper Race week | Rest | Half marathon pace 5 km (3.1 mi) 2×1 km @ half marathon pace, 400 m jogs | Rest | Easy 4 km (2.5 mi) | Rest | Easy 3 km (1.9 mi) with 4 strides | Race day 21.1 km (13.1 mi) | 33.1 km 20.6 mi |
Key sessions include easy warm-up and cool-down in their distance. Paces: easy, steady, tempo, threshold, intervals and race pace are explained under How to pace each run. Weeks 1–4 go by effort, with no pace targets.
Intermediate plan: 12 weeks, 5 runs a week
Tuesday key session, easy runs on Wednesday, Thursday and Saturday, long run on Sunday. Monday and Friday are rest days.
Before week 1
- You run 4–5 times a week, about 30–35 km (19–22 mi) in total.
- Your long run is already 12 km (7.5 mi) or more, and you have raced a 10K or a half before.
- You have up to 75 minutes on Tuesday and about 2 hours on Sunday.
| Week | Mon | Tue | Wed | Thu | Fri | Sat | Sun | Total |
|---|---|---|---|---|---|---|---|---|
| 1 Base | Rest | Hills 8 km (5 mi) 8×200 m uphill, jog down | Easy 5 km (3.1 mi) | Easy 5 km (3.1 mi) | Rest | Easy 4 km (2.5 mi) | Long run 12 km (7.5 mi) | 34 km 21.1 mi |
| 2 Base | Rest | Threshold 9 km (5.6 mi) 4×1 km @ threshold, 400 m jogs | Easy 6 km (3.7 mi) | Easy 5 km (3.1 mi) | Rest | Easy 4 km (2.5 mi) | Long run 13 km (8.1 mi) | 37 km 23 mi |
| 3 Base | Rest | Intervals 9 km (5.6 mi) 5×800 m @ interval pace, 400 m jogs | Easy 6 km (3.7 mi) | Easy 6 km (3.7 mi) | Rest | Easy 5 km (3.1 mi) | Long run 14 km (8.7 mi) | 40 km 24.9 mi |
| 4 Base Recovery | Rest | Threshold 7 km (4.3 mi) 3×1 km @ threshold, 400 m jogs | Easy 4 km (2.5 mi) | Easy 4 km (2.5 mi) | Rest | Easy 3 km (1.9 mi) | Long run 9 km (5.6 mi) | 27 km 16.8 mi |
| 5 Build | Rest | Tempo 10 km (6.2 mi) 5 km @ tempo | Easy 7 km (4.3 mi) | Easy 6 km (3.7 mi) | Rest | Easy 5 km (3.1 mi) | Long run 15 km (9.3 mi) | 43 km 26.7 mi |
| 6 Build | Rest | Intervals 10 km (6.2 mi) 6×800 m @ interval pace, 400 m jogs | Easy 7 km (4.3 mi) | Easy 7 km (4.3 mi) | Rest | Easy 5 km (3.1 mi) | Long run 17 km (10.6 mi) last 3 km @ half marathon pace | 46 km 28.6 mi |
| 7 Build | Rest | Threshold 11 km (6.8 mi) 3×2 km @ threshold, 400 m jogs | Easy 8 km (5 mi) | Easy 7 km (4.3 mi) | Rest | Easy 5 km (3.1 mi) | Long run 18 km (11.2 mi) last 3 km @ steady | 49 km 30.4 mi |
| 8 Build Recovery | Rest | Threshold 8 km (5 mi) 4×1 km @ threshold, 400 m jogs | Easy 5 km (3.1 mi) | Easy 5 km (3.1 mi) | Rest | Easy 4 km (2.5 mi) | Long run 11 km (6.8 mi) | 33 km 20.5 mi |
| 9 Peak | Rest | Half marathon pace 11 km (6.8 mi) 2×3 km @ half marathon pace, 400 m jogs | Easy 8 km (5 mi) | Easy 8 km (5 mi) | Rest | Easy 6 km (3.7 mi) | Long run 19 km (11.8 mi) last 3 km @ half marathon pace | 52 km 32.3 mi |
| 10 Peak | Rest | Intervals 12 km (7.5 mi) 5×1 km @ interval pace, 400 m jogs | Easy 9 km (5.6 mi) | Easy 8 km (5 mi) | Rest | Easy 6 km (3.7 mi) | Long run 20 km (12.4 mi) last 4 km @ half marathon pace | 55 km 34.2 mi |
| 11 Taper | Rest | Threshold 10 km (6.2 mi) 4×1 km @ threshold, 400 m jogs | Easy 7 km (4.3 mi) | Easy 6 km (3.7 mi) | Rest | Easy 5 km (3.1 mi) | Long run 14 km (8.7 mi) last 2 km @ half marathon pace | 42 km 26.1 mi |
| 12 Taper Race week | Rest | Half marathon pace 8 km (5 mi) 3×1 km @ half marathon pace, 400 m jogs | Easy 6 km (3.7 mi) | Easy 5 km (3.1 mi) | Rest | Easy 3 km (1.9 mi) with 4 strides | Race day 21.1 km (13.1 mi) | 43.1 km 26.8 mi |
Key sessions include easy warm-up and cool-down in their distance. Paces: easy, steady, tempo, threshold, intervals and race pace are explained under How to pace each run.
How the 12 weeks are built
- Base weeks 1–4
- Easy running, a weekend long run and a light key session: fartlek or hills. Beginners run these by effort, with no pace to hit yet. Week 4 drops the volume by about a third so the first block sinks in.
- Build weeks 5–8
- Threshold, intervals and tempo take over the key session, and the long run grows by about a kilometre a week. Week 8 is the second recovery week.
- Peak weeks 9–10
- The two biggest weeks. Half marathon pace shows up in the key session and at the end of the long run, so race pace feels familiar before you need it.
- Taper weeks 11–12
- Volume drops by about a fifth in week 11, then by half before race day. One short session at race pace keeps your legs sharp.
How to pace each run
Every pace in the plan is a band around your threshold pace, which you get from a 30-minute run test or a recent race. The examples are for a runner whose threshold pace is 5:00 per km (8:03 per mile).
| Run | How it feels | % of threshold speed | At 5:00 /km threshold |
|---|---|---|---|
| Easy and long runs | Conversational: you can talk in full sentences. | 75–82% | 6:06–6:40 /km · 9:49–10:44 /mi |
| Steady (a long run’s finish) | Comfortable but purposeful; still mostly easy. | 84–88% | 5:41–5:57 /km · 9:09–9:35 /mi |
| Tempo (marathon-pace effort) | Comfortably hard: a few words at a time. | 89–94% | 5:19–5:37 /km · 8:34–9:02 /mi |
| Threshold | Hard but controlled; you can say a word or two. | 97–102% | 4:54–5:09 /km · 7:53–8:18 /mi |
| Intervals | Hard, roughly your 5K race effort. | 104–110% | 4:33–4:48 /km · 7:19–7:44 /mi |
| Half marathon pace | Your goal pace: target time divided by 21.1 km. | From your goal time | 1:55 half marathon: 5:27 /km · 8:46 /mi |
By heart rate, easy means zones 1–2: at most 89% of your threshold heart rate, about 80% of your maximum. The heart rate zones calculator gives you the numbers in bpm. Don’t know your threshold pace? Enter a recent race in the race time predictor for a realistic goal, or read how to set your running training paces.
New to structured training? Run the beginner version’s first 4 weeks by effort and check your paces after week 4, once a few weeks of running have settled.
Key workouts in this plan
Fartlek
Short pick-ups of about 200 m at a brisk effort inside an easy run, with easy running in between. No pace target: brisk means clearly faster than easy and still in control. Weeks 1, 3 and 4 for beginners: short brisk pick-ups that wake the legs without a pace target. See the fartlek session for how to run it and scale it.
Hills
About 200 m up a moderate hill at a hard effort, then jog back down and go again. Strength and form, with less pounding than fast running on the flat. Week 1 (intermediate) and week 2 (beginner): strength and form before the faster sessions start. See the hill repeats for how to run it and scale it.
Tempo
One continuous block at tempo, after an easy warm-up. Settle into the pace in the first kilometre and hold it evenly. One continuous block at a comfortably hard effort in the build phase. See the tempo run for how to run it and scale it.
Threshold
Reps of 1 to 2 km at threshold with 400 m jogs. Split into reps, you can hold the pace cleanly for longer than in one block. The backbone of half marathon fitness: it raises the pace you can hold for a long time. See the threshold intervals for how to run it and scale it.
Intervals
800 m to 1 km reps at interval pace with 400 m jogs. Run every rep at the same pace; the last one should feel hard, not desperate. Faster than race pace, so half marathon pace feels easier by comparison. See the VO2max intervals for how to run it and scale it.
Short of time on a Tuesday? 400 m repeats work in the same slot, with the same jogs.
Half marathon pace
Reps or a long-run finish at your goal half marathon pace. Practise the rhythm, your breathing and, on the long run, your race-day gels and drinks. Weeks 9 to 12: race-pace reps on Tuesday and a race-pace finish to the long run. See the race time predictor to turn a recent 10K into a goal pace.
Race week
Tuesday’s short half-marathon-pace session is the last hard run. Keep Thursday easy, rest on Friday, and run 3 km on Saturday with 4 strides of about 20 seconds. Start the race at goal pace or a little slower, and save any push for the last 5 km.
Adjusting the plan to your life
- Missed a run or two: let them go and carry on with the plan as written. If it was the key session, move it to the next easy day only when there is a rest or easy day between it and the long run.
- Missed a week or been ill: once you feel well, run 2–3 easy days, then repeat the last week you completed before moving on. Don’t squeeze two weeks into one.
- Travelling: keep the key session and the long run, drop easy runs first, and keep the two hard days apart.
- Long run on Saturday instead: swap Saturday and Sunday. With a different day off, shift the whole week and keep at least one easy or rest day between the key session and the long run.
- Race on a different date: repeat early weeks if you have more time; start later only if you already run that week’s distance. The last 2 weeks always stay the taper.
- Feeling flat for days: swap the next key session for an easy run. An easy week costs you less than a forced one.
Get this plan built around your week
TextFit’s coach builds your half marathon plan from your race date, target time, the days you can run, your day off and a recent result in your own words (“10K in 52 minutes”), with the same rules as the tables above.
- Your paces, on your watch. Each run goes to your Garmin or Apple Watch as a structured workout with pace targets from your threshold, and the next 7 days are pushed automatically.
- Change it in one sentence. “I’m travelling Thursday, move the long run to Saturday” or “I had a cold, ease this week”: the coach changes the plan and shows each change with Undo.
- It reads your runs and recovery. After a key session you see how many reps stayed in the target band, and the recovery check compares your HRV, resting heart rate and sleep with your own normal range.
- Strength if you want it: 1–2 sessions a week, on an easy day or after the key session, never on the day before a key session or the long run.
More on how it works for runners: the AI running coach.
Your half marathon plan on your Garmin or Apple Watch
Tell the coach your race date and a recent result. It builds your first two weeks with your paces and keeps the next 7 days on your watch.
14 days free, then $14.99/month or $99.99/year. Cancel anytime in your App Store settings.
Start your 14-day free trial FAQ
Can I train for a half marathon in 12 weeks?
Yes, if you already run regularly. The beginner version starts at 20 km (12 mi) a week with a 8 km long run; if that is more than you run now, spend a few weeks building to it first, or follow a run-walk approach.
How many kilometres (miles) a week should I run for a half marathon?
In this plan, beginners build from 20 km (12 mi) to 35 km (22 mi) a week on 4 runs, and intermediate runners from 34 km (21 mi) to 55 km (34 mi) on 5 runs. Volume never rises more than 10% from one week to the next.
Is this half marathon plan good for beginners?
Yes. The beginner version has 4 runs a week, only one of them hard, and runs the first 4 weeks by effort instead of pace. You should be running about 3 times a week and comfortable with 8 km before week 1.
What pace should my long runs be?
Easy: you can talk in full sentences. In pace terms that is 75–82% of your threshold speed, for example 6:06–6:40 per km (9:49–10:44 per mile) for a runner whose threshold pace is 5:00 per km. In the peak weeks the last 2 to 4 km go at half marathon pace.
How long should my longest run be before a half marathon?
16 km in the beginner version and 20 km in the intermediate one, both in week 10, two weeks before the race. You don’t need to run the full 21.1 km in training; race-day freshness and the taper carry you the rest of the way.
Can I download this plan as a PDF?
Yes. Use the Print this plan button above each table and choose Save as PDF in the print dialog. It prints that version’s 12 weeks with the pace key, without the rest of the page.
My race is in 10 or 14 weeks. Can I still use it?
With 14 weeks, repeat weeks 1 and 2 before carrying on with week 3. With 10 weeks, start at week 3 only if you already run that week’s volume and long run; otherwise start at week 1 and skip week 4, the first recovery week.
More plans and guides
- 16-week marathon training plan: Beginner, 4 runs a week up to 60 km (37 mi), or intermediate, 5 runs a week up to 79 km (49 mi). The long run peaks at 32 km (20 mi) in week 14.
- All training plans
- Interval training for a half marathon : which sessions to run and how to progress them.
- Best marathon training apps: Runna, Garmin Coach, Nike Run Club and more, compared.