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Training plan

12-week half marathon plan for a ready runner

Use a 12-week half marathon plan with a current running base, protected key sessions and practical missed-week rules.

Updated Aug 9, 2026

Compare the plan

Your path

Build the capacity

The decision this page helps you make

A 12-week half-marathon build works best when easy running is already routine and the plan does not need to create the entire base.

Understand this stageSet a conservative pace range

Your training plan

Start with the weeks, not the fine print

See what each week is trying to achieve, then choose the number of training days that fits your life. The schedule comes first; workouts, adjustments, and calculators are below it.

Start at week 1
Length
12 weeks
Frequency
3–6 days
Easy session
~45 min
Long session
~1 hr 45 min
Check readiness and safety before week 1

This plan starts from

  • • You can run 30 minutes comfortably 3–4×/week.
  • • You can complete a 60–75 minute easy session and recover normally over the next two days.
  • • You’re willing to keep easy days easy so workouts stay high-quality.

Pause and reassess when

  • • Pain that changes your gait (scale down and get assessed).
  • • A rapidly increasing injury history with volume increases.
  • • Illness symptoms that worsen with training load.

This is general training information, not medical advice.

Week by week

Your 12-week plan

Start with the first phase. Open later phases when you are ready for them. Each week shows the long session, priority work, and a load guide when one is available.

  1. Base

    Weeks 1–3

    Build consistency and durable easy volume.

  2. Build

    Weeks 4–7

    Add quality while protecting recovery.

  3. Peak

    Weeks 8–10

    Train race-specific pacing and fueling.

  4. Taper

    Weeks 11–12

    Reduce load; keep rhythm; arrive fresh.

BaseWeeks 1–3
View 3 weeks

Build consistency and durable easy volume.

Opens with: 1h long run (steady finish when recovered)

  1. Week

    1

    Base

    Build consistency and durable easy volume.

    Long session
    1h long run (steady finish when recovered)
    Priority sessions
    Strides + controlled aerobic · Hill sprints (short) + strength

    Weekly load guide: 29–47 km

  2. Week

    2

    Base

    Build consistency and durable easy volume.

    Long session
    1h 7m long run (steady finish when recovered)
    Priority sessions
    Strides + controlled aerobic · Hill sprints (short) + strength

    Weekly load guide: 30–48 km

  3. Week

    3

    Base

    Build consistency and durable easy volume.

    Long session
    1h 14m long run (steady finish when recovered)
    Priority sessions
    Strides + controlled aerobic · Hill sprints (short) + strength

    Weekly load guide: 31–50 km

BuildWeeks 4–7
View 4 weeks

Add quality while protecting recovery.

Opens with: 1h 9m long run (steady finish when recovered) · 1 cutback week

  1. Week

    4

    BuildCutback

    Add quality while protecting recovery.

    Long session
    1h 9m long run (steady finish when recovered)
    Priority sessions
    Tempo or cruise intervals · Long-run progression

    Weekly load guide: 32–51 km

  2. Week

    5

    Build

    Add quality while protecting recovery.

    Long session
    1h 29m long run (steady finish when recovered)
    Priority sessions
    Tempo or cruise intervals · Long-run progression

    Weekly load guide: 33–53 km

  3. Week

    6

    Build

    Add quality while protecting recovery.

    Long session
    1h 36m long run (steady finish when recovered)
    Priority sessions
    Tempo or cruise intervals · Long-run progression

    Weekly load guide: 34–54 km

  4. Week

    7

    Build

    Add quality while protecting recovery.

    Long session
    1h 43m long run (steady finish when recovered)
    Priority sessions
    Tempo or cruise intervals · Long-run progression

    Weekly load guide: 35–56 km

PeakWeeks 8–10
View 3 weeks

Train race-specific pacing and fueling.

Opens with: 1h 34m long run (steady finish when recovered) · 1 cutback week

  1. Week

    8

    PeakCutback

    Train race-specific pacing and fueling.

    Long session
    1h 34m long run (steady finish when recovered)
    Priority sessions
    Threshold + speed endurance · Long run with controlled finish

    Weekly load guide: 36–57 km

  2. Week

    9

    Peak

    Train race-specific pacing and fueling.

    Long session
    1h 58m long run (steady finish when recovered)
    Priority sessions
    Threshold + speed endurance · Long run with controlled finish

    Weekly load guide: 37–59 km

  3. Week

    10

    Peak

    Train race-specific pacing and fueling.

    Long session
    2h 5m long run (steady finish when recovered)
    Priority sessions
    Threshold + speed endurance · Long run with controlled finish

    Weekly load guide: 38–60 km

TaperWeeks 11–12
View 2 weeks

Reduce load; keep rhythm; arrive fresh.

Opens with: 1h 40m long run (steady finish when recovered)

  1. Week

    11

    Taper

    Reduce load; keep rhythm; arrive fresh.

    Long session
    1h 40m long run (steady finish when recovered)
    Priority sessions
    Short tempo + strides · Easy aerobic + sleep focus

    Weekly load guide: 39–62 km

  2. Week

    12

    Taper

    Reduce load; keep rhythm; arrive fresh.

    Long session
    1h 15m long run (steady finish when recovered)
    Priority sessions
    Short tempo + strides · Easy aerobic + sleep focus

    Weekly load guide: 40–63 km

Weekly schedule

Choose the rhythm you can repeat

The phase progression stays the same. Your choice only changes how you spread the priority sessions, easy work, and recovery across the week.

4 days/week (Beginner-friendly)

4 days/week · Beginner

  • • Best if your schedule is tight or you’re building durability.
  • • Keep workouts conservative; consistency is the win.

3 days/week (Lower-frequency option)

3 days/week · Beginner

  • • Best if you’re time-limited, returning from time off, or managing impact.
  • • Protect the long run. Keep the workout controlled. Add strength on 1–2 non-run days.

5 days/week (Balanced week)

5 days/week · Intermediate

  • • A strong default: enough volume to progress, enough recovery to absorb it.
  • • One workout + one long run focus per week is plenty.

6 days/week (Advanced, recovery-dependent)

6 days/week · Advanced

  • • Only if your recovery stays stable for 2–3 weeks in a row.
  • • The extra day should be truly easy or short recovery.

Adjust the plan

What changed this week?

Open the situation that matches your week. Do not cram missed work into the next few days.

Missed workout
  • • Don’t ‘make up’ missed sessions by doubling hard days.
  • • If you miss one workout: keep the long run, skip the extra intensity.
  • • If you miss a week: repeat the last week you completed confidently.
Low sleep week
  • • Cut intensity before you cut easy volume: keep it aerobic.
  • • Shorten the long run by 15–25% if sleep is poor for multiple nights.
  • • Add one extra rest day if stress is high.
Fatigue signals
  • • If your easy pace feels hard: keep the day easy and shorten duration.
  • • If soreness persists >48h: remove the next hard session.
  • • If motivation tanks + HR drifts: treat it like a recovery week.
Pain or injury
  • • Pain that changes form is a stop signal — do not ‘push through’.
  • • Swap running for low-impact cardio until pain-free in daily life.
  • • Return with short easy runs; add intensity last.
Travel week
  • • Protect one key session: either the long run or the workout — not both.
  • • Use time-based training (minutes) when terrain/schedule changes.
  • • Keep strength micro-sessions (10–15 min) instead of skipping completely.

Workout guide

Understand the sessions in the plan

Use this as a reference when a workout name appears in your week. You do not need to read every entry before starting.

Easy aerobic run

Why: Build volume without accumulating fatigue.

Do: 30–60 min at conversational effort. If you can’t talk in full sentences, it’s too hard.

Swap with

  • • Bike or easy elliptical for the same time if impact is an issue.

Stop or scale back when

  • • Pain that changes your gait.
  • • Easy pace drifting harder to hold the same effort.
Strides + drills

Why: Improve mechanics and economy without a heavy metabolic cost.

Do: After an easy run: 6–10 × 15–20 sec fast-but-relaxed, full walk/jog recovery.

Swap with

  • • 6–8 × 20 sec hill strides for reduced impact.

Stop or scale back when

  • • Sprint-like intensity that leaves you sore.
  • • Tight hamstrings or sharp calf pain.
Tempo / cruise intervals

Why: Raise sustainable pace and teach controlled discomfort.

Do: 2–4 × 8–12 min at ‘comfortably hard’ with 2–3 min easy between.

Swap with

  • • 20–30 min steady tempo continuous if you pace well.

Stop or scale back when

  • • Breathing out of control early.
  • • Needing to ‘surge’ to hold the last reps.
Interval session (VO₂-ish)

Why: Sharpen speed and economy for faster running at a lower cost.

Do: 5–8 × 3 min hard with 2–3 min easy; stay controlled, finish with form.

Swap with

  • • 6–10 × 400m on the track with equal jog recovery.

Stop or scale back when

  • • All-out reps.
  • • Form collapse or sharp pains.
Long run (easy with structure)

Why: Build durability and rehearsals for race-day pacing and fueling.

Do: Mostly easy. When stable: finish the last 15–25 min steady (not a race).

Swap with

  • • Split long run (AM/PM) on high-stress weeks; keep total time similar.

Stop or scale back when

  • • Long-run pace creeping; next-day fatigue lasting >48h.
  • • Fueling causing repeated GI issues (adjust and practice).
Threshold + fast finish

Why: Practice the exact intensity you want to execute on race day.

Do: 3 × 10 min threshold, then 10–15 min steady finish if you’re recovered.

Swap with

  • • Progression run: easy → steady → controlled hard (only when recovered).

Stop or scale back when

  • • Needing to ‘push’ early.
  • • Shin/calf pain that escalates with pace.
Strength (short + consistent)

Why: Support durability and running economy with minimal interference.

Do: 2×/week, 20–35 min: hips, calves, hamstrings, trunk. Leave 1–2 reps in the tank.

Swap with

  • • Bodyweight circuit if you’re traveling.

Stop or scale back when

  • • Heavy DOMS that ruins key sessions.
  • • Form breakdown under load.

More guidance

Read schedule examples and special cases

Open this for day-of-week examples, run/walk options, goal-specific notes, and useful links.

Is this plan length right for you?

Twelve weeks is a focused half-marathon build. It works best when easy running frequency already exists and the opening long run is familiar.

This plan is best for a runner who can already complete three weekly runs and an easy longer outing. Before week one, confirm that the opening volume does not require a catch-up phase. If that evidence is missing, choose the 16-week half marathon plan instead of compressing the opening phase.

Decision pointKeep the plan whenAdjust when
Opening loadThe first week resembles recent repeatable trainingThe first week would be a major jump
Key sessionone threshold-oriented session and the easy long runEffort, form or normal movement deteriorates
Support workEasy volume and strength fit around the priorityRecovery cost compromises the next key day
Missed weekResume from demonstrated capacitySeveral sessions would need to be stacked

Make the first decision before adding load

Compare week one with the previous four weeks and lengthen the runway if frequency, long-run duration or intensity all jump together. Record completed sessions, effort, normal movement and next-day function. Progress one major variable at a time. If a session is missed, keep the next important workout only when recovery and timing support it; do not combine two hard sessions to catch up.

Protect one threshold-oriented session and the easy long run. Reduce secondary repetitions and optional easy volume before removing the work most specific to the goal. Use the race-time predictor for calculations, then keep the result subordinate to current training evidence.

The Physical Activity Guidelines support ability-aware progression, while the systematic review on strength and running describes average evidence rather than one mandatory exercise prescription. Neither source guarantees a finish time or makes this plan medical clearance. Stop for severe symptoms or pain that changes normal movement and seek appropriate care.

How to use this plan

Choose one weekly rhythm and follow it for 2 weeks before changing it. Keep easy runs easy so you can recover from the long run and one quality session.

Sample weekly schedules (3–6 days/week)

These are example templates. You can move days around, but keep this order: workout → recovery → long run.

3 days/week (minimum effective dose)

  • Day 1: Easy run + 4–6 strides (optional)
  • Day 2: Quality workout (controlled)
  • Day 3: Long run (easy; practice fueling on longer days)

4 days/week (beginner-friendly)

  • Day 1: Easy run + short strength
  • Day 2: Quality workout (controlled)
  • Day 3: Easy run (keep it truly easy)
  • Day 4: Long run (easy; progress slowly)

5 days/week (balanced default)

  • Day 1: Easy run
  • Day 2: Quality workout
  • Day 3: Easy run + short strength
  • Day 4: Easy run (or steady when recovered)
  • Day 5: Long run

6 days/week (advanced)

  • Add one extra short recovery run (very easy).
  • Keep the number of hard sessions the same; the extra day is for aerobic volume, not intensity.

Run/walk option (allowed)

Run/walk can help you manage effort, build durability, and protect recovery.

  • Keep intensity low (conversation test).
  • Progress one variable at a time (longer run intervals before faster pace).
  • On long runs, aim for repeatable time on feet and recovery within the next 48 hours.

Guide: Run/walk marathon training plan

If you’re over 50 (masters runners)

The plan is the same; the recovery math changes.

  • Keep easy days truly easy so workouts stay effective.
  • Treat strength as part of training with 2 short sessions each week.
  • If niggles accumulate, reduce intensity first — not sleep.

Guide: Marathon training plan over 50

Training for a time goal (sub-4 / sub-2 / PRs)

Use pace tools to translate a goal into numbers — then train by effort on easy days so you can absorb the hard work.

Guide: Sub-2 hour half marathon training plan

Common glossary terms (so the plan language is clear):

Tools

Use numbers only when they help the plan

Start with the weekly schedule. Use a calculator when you need pace, fueling, cutoff, or printable-plan details.

Running pace calculatorOpen the tool with this plan’s defaults.Race time predictorOpen the tool with this plan’s defaults.
Use interactive calculators on this page
Loading pace calculator…
Loading race time predictor…

Why this structure

The principles behind the plan

  • Consistency beats hero sessions: durable aerobic volume is the engine.
  • Cutback weeks create space to absorb training before fatigue builds too far.
  • A small workout library repeated with progression is more effective than endless novelty.
  • Fueling practice is a skill — you train it like pacing.

Adaptive AI coach for iPhone

Let your coach adapt the plan.

Your adaptive AI coach reviews completed work and adjusts upcoming sessions after missed training, poor sleep, unusual fatigue, or a disrupted week.

Start training now

FAQs

Who should use 12-week half marathon plan for a ready runner?

It is best suited to a runner who can already complete three weekly runs and an easy longer outing and whose recent training makes the opening week familiar.

What should I do after a missed week?

Resume from demonstrated capacity, preserve recovery spacing and do not stack missed hard sessions into the next week.

Should I progress when a session feels unusually hard?

Hold or reduce the load when effort, symptoms, form or next-day function shows that the current dose is not yet repeatable.

Is a 12-week half marathon plan enough time?

It can work if you already have a base. If you’re starting from scratch, extend the timeline and prioritize consistency over intensity.

How many hard sessions should I do per week?

A good default is one quality workout plus one long-run focus. If you add more, it should be short and only when recovery is stable.

What if I miss a run?

Don’t cram. Keep the next session easy, protect the long run, and resume structure when your legs feel normal again.

How do I keep easy runs truly easy?

Use a conversational effort check: you should be able to talk in full sentences. If not, slow down or add walk breaks.

Do I need strength training?

Two short strength sessions per week can support durability. Keep them consistent and avoid soreness before key runs.

When should I practice fueling?

For half marathons, fueling is simpler, but practicing hydration and pre-run carbs still helps you race consistently.

Keep going

16-Week Half Marathon Plan: Build, Practise and Taper

Use a 16-week half marathon plan with a foundation phase, controlled pace practice and explicit adjustment rules.

Open guide

Running Race Time Predictor: Estimate a Range, Not a Promise

Estimate an equivalent race-time range from a recent performance, then adjust for distance gap, terrain, weather and training specificity.

Open guide

Strength Training for Endurance Athletes: Evidence Lab

Review systematic evidence on strength training for endurance performance, then translate it into a minimal, recoverable weekly decision.

Open guide

Sources