13.1 miles · 20 weeks
20-week half marathon training plan
Twenty weeks is the gentlest way to reach a half marathon. It's built for runners starting from very little who want to get there safely.
The sample starts at just 7 miles a week on three runs. Mileage rises in small steps to 16.5 miles a week, and the long run builds from 3 to 9 miles before a 2-week taper.
The plan
20-week half marathon plan: week by week
Beginner runner, 3 runs a week, starting from 7 miles a week. 20 weeks to race day.
- 20
- weeks
- 16.5
- mi peak week
- 9
- mi longest run
- 209
- 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 | 7 mi | 3 mi | Easy running and strides |
| 2 | Base | 7.5 mi | 3.5 mi | Easy running and strides |
| 3 | Baserecovery | 5.5 mi | 3 mi | Recovery week: all easy |
| 4 | Base | 8 mi | 4 mi | Easy running and strides |
| 5 | Base | 8.5 mi | 4.5 mi | Easy running and strides |
| 6 | Baserecovery | 6 mi | 3 mi | Recovery week: all easy |
| 7 | Build | 9 mi | 4.5 mi | Tempo run 3 mi |
| 8 | Build | 9.5 mi | 5 mi | Tempo run 3 mi |
| 9 | Buildrecovery | 7 mi | 3.5 mi | Recovery week: all easy |
| 10 | Build | 10 mi | 5.5 mi | Tempo run 3 mi |
| 11 | Build | 11 mi | 6 mi | Tempo run 3 mi |
| 12 | Buildrecovery | 8 mi | 4 mi | Recovery week: all easy |
| 13 | Build | 12 mi | 6.5 mi | Tempo run 3 mi |
| 14 | Build | 13 mi | 7 mi | Tempo run 3 mi |
| 15 | Peakrecovery | 9.5 mi | 4.5 mi | Recovery week: all easy |
| 16 | Peak | 14 mi | 7.5 mi | Tempo run 3 mi |
| 17 | Peak | 15 mi | 8 mi | Tempo run 3 mi |
| 18 | Peak | 16.5 mi | 9 mi | Tempo run 3 mi |
| 19 | Taper | 12 mi | 6 mi | Short tempo 3 mi |
| 20 | Race week | 20 mi | 13.1 mi | Race week: easy runs, then race day |
Sample week
20-week half marathon plan: a peak week, day by day
Week 18 of 20, 16.5 miles. Every run in your own plan comes with its distance, structure and target pace.
Week 18 of 20
Peak- MonRest
- TueEasy runRPE 3 to 4 · conversational4.5mi
- WedRest
- ThuTempo runRPE 7 · comfortably hard, about one-hour race effort3mi
- FriRest
- SatRest
- SunLong runRPE 3 to 4 · conversational9mi
Who this plan is for
- You run a little now, maybe a 5K a couple of times a week.
- You want plenty of time and recovery.
- Your half marathon is about five months away.
How to adjust it
- Starting from zero? Build up with a beginner 5K plan first.
- Ready for more? Add a fourth run in the planner.
- Use run/walk on long runs whenever you like.
Why this 20-week half marathon plan works
Tiny steps add up
Small weekly increases feel easy, and over 20 weeks they take you from a few miles to race distance.
Recovery every third week
Lighter weeks give your body time to absorb the training.
Walk breaks welcome
Run/walk on long runs is a proven way to go further with less fatigue.
20-week half marathon plan FAQ
Can I train for a half marathon from very little running?
Yes, with enough time. This 20-week plan starts at 7 miles a week and builds gradually.
How long is the longest run?
This sample peaks at 9 miles. Race-day adrenaline and the taper carry you through the rest.
What if I can't run continuously yet?
Start with a beginner 5K plan, which uses run/walk, then move to this plan.
How many days a week will I run?
Three. Cross-training on other days is optional but helpful.
Is 20 weeks too long?
For low-mileage runners it's ideal: small increases and room for missed weeks.
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).