13.1 miles · 12 weeks
12-week half marathon training plan
A 12-week half marathon plan gives you time to build endurance and add some speed. It suits runners who already run regularly and want to run a strong race, not just finish.
This sample runs 4 days a week from 16 miles. Expect intervals and tempo runs in the build phase, weekly mileage up to 29 miles and a long run that peaks at 11 miles before a 2-week taper.
The plan
12-week half marathon plan: week by week
Intermediate runner, 4 runs a week, starting from 16 miles a week. 12 weeks to race day.
- 12
- weeks
- 29
- mi peak week
- 11
- mi longest run
- 254
- mi in total
Weekly distance
Training efforts
- RecoveryRecovery runsRPE 2 · very easy, slower than you think
- EasyEasy and long runsRPE 3 to 4 · conversational
- SteadySteady runsRPE 5 · steady, can speak in short sentences
- Race paceRace-pace workGoal race effort
- ThresholdTempo, cruise repsRPE 7 · comfortably hard, about one-hour race effort
- Interval800 m intervalsRPE 8 to 9 · hard, about 5K race effort
Add a recent race or goal time in the builder for exact paces.
| Week | Phase | Distance | Long run | Key sessions |
|---|---|---|---|---|
| 1 | Base | 16 mi | 6 mi | Steady run 3 mi |
| 2 | Base | 17.5 mi | 6.5 mi | Steady run 3 mi |
| 3 | Base | 19 mi | 7 mi | Steady run 3 mi |
| 4 | Baserecovery | 14 mi | 4.5 mi | Steady run 3 mi |
| 5 | Build | 20.5 mi | 8 mi | Intervals 3 mi · Tempo run 3 mi |
| 6 | Build | 22.5 mi | 8.5 mi | Intervals 3 mi · Tempo run 3.5 mi |
| 7 | Build | 24.5 mi | 9.5 mi | Intervals 3.5 mi · Tempo run 4 mi |
| 8 | Buildrecovery | 18 mi | 6.5 mi | Intervals 3 mi |
| 9 | Peak | 26.5 mi | 10 mi | Tempo run 4.5 mi · Intervals 3.5 mi |
| 10 | Peak | 29 mi | 11 mi | Tempo run 4.5 mi · Intervals 4 mi |
| 11 | Taper | 21.5 mi | 7.5 mi | Short tempo 3.5 mi |
| 12 | Race week | 25 mi | 13.1 mi | Race week: easy runs, then race day |
Sample week
12-week half marathon plan: a peak week, day by day
Week 10 of 12, 29 miles. Every run in your own plan comes with its distance, structure and target pace.
Week 10 of 12
Peak- MonRest
- TueTempo runRPE 7 · comfortably hard, about one-hour race effort4.5mi
- WedEasy runRPE 3 to 4 · conversational9.5mi
- ThuRest
- FriIntervalsRPE 8 to 9 · hard, about 5K race effort4mi
- SatRest
- SunLong run, fast finishRPE 3 to 4 · conversational11mi
Who this plan is for
- You run three or four days a week now.
- Your race is about three months away.
- You'd like to add some faster running.
How to adjust it
- Prefer five runs? The planner spreads the mileage across them.
- Add a time goal and race-pace sessions use it.
- Change the long-run day and the week rebalances.
Why this 12-week half marathon plan works
Speed in small doses
One interval session a week is enough to make race pace feel more comfortable.
Tempo for stamina
Sustained comfortably hard running is the most race-specific session for the half.
A 2-week taper
Two lighter weeks let you race at full strength.
12-week half marathon plan FAQ
Is 12 weeks enough for a half marathon?
Yes, for most runners who already run a few times a week. It's the most popular half marathon plan length.
How many miles a week should I run for a half marathon?
This sample peaks at 29 miles a week. Beginners often finish well on less; intermediate runners usually peak in the 20s or 30s.
Should I run the full 13.1 miles in training?
It isn't necessary. This plan peaks at 11 miles, which is enough preparation.
What's a good half marathon goal time?
Use a recent 10K: multiply your 10K time by about 2.2 for a realistic half marathon estimate.
When should I start?
Twelve weeks before race day. The builder counts back from your date automatically.
What's free and what's paid
Free: the plan outline (phases, weekly mileage and paces) plus the first 2 weeks day by day. Every session, the PDF and calendar sync come with Monthly ($13/month, cancel anytime), Yearly ($70/year) or Lifetime ($100 once, a one-time payment).