Build The Long Run
Move from comfortable weekly running toward a long run that makes 13.1 feel familiar, not shocking.
Race plan field guide
12 Week Half MarathonTraining Plan
Twelve weeks is enough time to build the long run, add controlled tempo work, and arrive ready without cramming the final month.
Create My 12 Week Half PlanNo card required · preview the first two weeks
Week sheet · Half Marathon
Compare the training rhythm
MonRecoveryRest
TueWorkoutEasy 4k
WedRecoveryRest
ThuWorkoutEasy 5k
FriRecoveryRest
SatWorkoutLong 8k
SunRecoveryRest
The race brief
A practical 12 week half marathon build
This page is for runners who can train consistently for about three months and want the plan shaped around real weekly availability, not a fixed PDF.
Use 12 weeks the right way
Add Pace Without Forcing It
Use tempo and goal-pace blocks after the easy running is stable, not as a substitute for it.
Training architecture
What a Half Marathon plan usually includes
Use these ranges as a planning baseline. Your generated schedule adjusts them around current fitness, available days, race date, and goal pace.
Typical length8-16 weeks
Weekly volume20-45 miles / 32-72 km
Long-run peak8-13 miles / 13-21 km
What matters for a 12 week half marathon
Start from your real base
Twelve weeks works when you already have some consistency. If the first long run scares you, take a longer build.
Do not race the long run
Long runs teach durability. Add pace later, and only when the distance itself is no longer the hard part.
Use tempo with restraint
A controlled tempo day helps half marathon fitness. Two or three hard days in a week usually does not.
Preview a 12 week half marathon week
This is the kind of middle-block week a 12 week plan might build toward once the long run is stable.
| Day | Focus | Purpose |
|---|---|---|
| Mon | Rest | No running. Keep it boring. |
| Tue | Tempo | 10 min easy, 3 x 8 min tempo, 10 min easy. |
| Wed | Easy | 35-45 min relaxed. |
| Thu | Medium long | 60 min easy with the final 10 min steady if you feel good. |
| Fri | Rest | Save the legs for the long run. |
| Sat | Long run | 10 miles / 16 km easy, practice the fuel you might use on race day. |
| Sun | Recovery | Optional 25 min easy or full rest. |
Which level should you choose?
Beginner
Use this if the goal is to finish well and build the long run without rushing the jump in distance.
Intermediate
Use this if you already run 10K comfortably and want tempo work plus longer aerobic runs.
Advanced
Use this if you can handle longer midweek runs and race-pace work inside long runs.
How long should the plan be?
8 weeks
A short block for runners who already have a strong long-run base.
10-12 weeks
The safest fit for many runners moving from regular 10K training into half marathon work.
14-16 weeks
Better for first-time half marathoners or anyone building weekly volume carefully.
Common mistakes to avoid
- Making every long run a race simulation
- Undertraining fuel and pacing before race day
- Choosing aggressive mileage without an endurance base
Before the first week
Calibrate this Half Marathon plan
Check the goal, paces, and training zones before turning a general plan into your weekly schedule.
Check 01
Predict your Half Marathon finish time
Use a recent race or time trial to choose a realistic goal before training starts.
Check 02Calculate training paces
Convert goal time, distance, and pace into numbers you can use on workout days.
Check 03Estimate VO2 max
Benchmark current fitness from race time or running pace before setting plan intensity.
Check 04Set training zones
Map easy, tempo, threshold, and interval efforts to useful intensity ranges.
What your 12 week half plan should include
- 12 week plan duration prefilled
- Long-run progression matched to current fitness
- Tempo work placed with recovery around it
- Fuel practice reminders for longer runs
- 4 day/week default with room to adjust
- Goal pace support when you have a target time
Turn the field guide into your training week.
Preview two personalised weeks free. Unlock the full race plan only if it fits.
12 Week Half Marathon Plan FAQs
The practical questions runners usually need answered before choosing a training block.
Next course markers
Keep comparing
Compare related plans and supporting guidance before choosing the training block that matches your race.
Calibration bench
Check the inputs
Use the calculators to pressure-test pace and intensity before turning this guide into a schedule.
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