12-Week Half Marathon Training Plan
Wanting peak long-run miles and needing legs that still turn over on Tuesday often conflict. Force the peak week on a shaky base and race day becomes damage control. This 12-week plan is for runners who can already run ~45–60 minutes easy. Phases: aerobic foundation → build → sharpen/taper. Set easy intensity with the Zone 2 Calculator and easy run pace guide; check goals with the Race Predictor and Pace Chart. Calorie awareness: calories calculator. Predictors lie sometimes — read why predictors are often wrong.
Phase Map
- Weeks 1–4: easy volume + short tempo at HM effort
- Weeks 5–8: longer tempo/long runs; optional faster reps
- Weeks 9–12: peak specific work, then taper
- Race day: first 5K patient; fuel what you practiced
Numeric scenario: Build-phase long run 90 min with last 25 min at HM pace. If HM segments average >10–15 sec/km slower than goal and the following easy day is still elevated (+5 bpm RHR or dead legs), cut next week’s long run by 10–15 min and drop the second quality day once.
Half marathon success is boring easy miles, one honest quality stimulus, and a long run that teaches patience. One missed week isn’t a crisis; three ignored easy days is.
Decision rule: cut intensity before volume when fatigued. If long runs repeatedly blow up, extend the foundation phase instead of forcing peak mileage.
Phase Schedules
Typical week (Weeks 1–4)
- MonEasy 40 min
- TueTempo 20–25 min at HM pace
- WedEasy 35 min
- ThuEasy 40 min
- SatLong run — 70 min (W1), 75 min (W2), 80 min (W3), 65 min easy (W4 recovery)
Week 6 example
- MonEasy 45 min
- TueTempo 35 min at HM pace
- WedEasy 40 min
- Thu4 × 1 mile at 10K pace, 2 min jog
- SatLong 90 min (last 25 min at HM pace)
Week 8 example (peak week)
- MonEasy 45 min
- TueTempo 40 min at HM pace
- WedEasy 40 min
- ThuEasy 45 min
- SatLong 95 min
Week 10
- MonEasy 40 min
- Tue3 × 1 mile at HM pace
- WedEasy 35 min
- SatLong 75 min
Week 11
- MonEasy 35 min
- TueTempo 20 min at HM pace
- WedEasy 30 min
- SatLong 60 min
Week 12 (race week)
- MonEasy 25 min
- Wed3 × 1K at HM pace
- FriRest
- SunHalf marathon
How to Slide Weeks Without Panic
Later in the build, short HM-pace segments can help — keep most of the long run easy so recovery survives. If you aren’t comfortable with ~30–45 min easy runs most days of a week, finish a 10K block first.
Practical Takeaway
Taper and race the plan you actually completed — not the fantasy schedule you screenshot in week 1.
FAQ
Should long runs include race-pace miles?
Later in the build, short HM-pace segments can help — keep most of the long run easy so recovery survives.