At a glance
Plan length
12 weeks
Built with phases, cutbacks, and a taper you can actually execute.
Weekly rhythm
4–6 days/week
Choose one variant and follow it for 2 weeks before tweaking.
Typical session time
Easy: ~45m • Long: ~105m
Prefer consistent minutes over heroic single sessions.
Readiness gate
- • You can run 30 minutes comfortably 3–4×/week.
- • You can complete a long-ish session (60–75 min) without being wrecked for 2 days.
- • You’re willing to keep easy days easy so workouts stay high-quality.
Default recommendation
4 days/week (Beginner-friendly)
Start here to reduce decision fatigue. Customize only after your first two weeks feel stable.
- • Best if your schedule is tight or you’re building durability.
- • Keep workouts conservative; consistency is the win.
Safety first
This is general training information, not medical advice.
- • 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.
Coaching beta
Want this adapted to your recovery?
Get coach-style adjustments when you miss sessions, sleep poorly, or feel fatigue signals.
Week by week
Structure you can scan
Use this as your decision map: what matters this week, what the long run is doing, and where you should back off.
| Week | Phase | Focus | Long session | Key workouts | Notes |
|---|---|---|---|---|---|
| 1 | Base | Build consistency and durable easy volume. | 1h long run (steady finish when recovered) | Strides + controlled aerobic • Hill sprints (short) + strength | — |
| 2 | Base | Build consistency and durable easy volume. | 1h 7m long run (steady finish when recovered) | Strides + controlled aerobic • Hill sprints (short) + strength | — |
| 3 | Base | Build consistency and durable easy volume. | 1h 14m long run (steady finish when recovered) | Strides + controlled aerobic • Hill sprints (short) + strength | — |
| 4 | Build | Add quality while protecting recovery. | 1h 9m long run (steady finish when recovered) | Tempo or cruise intervals • Long-run progression | Cutback week |
| 5 | Build | Add quality while protecting recovery. | 1h 29m long run (steady finish when recovered) | Tempo or cruise intervals • Long-run progression | — |
| 6 | Build | Add quality while protecting recovery. | 1h 36m long run (steady finish when recovered) | Tempo or cruise intervals • Long-run progression | — |
| 7 | Build | Add quality while protecting recovery. | 1h 43m long run (steady finish when recovered) | Tempo or cruise intervals • Long-run progression | — |
| 8 | Peak | Train race-specific pacing and fueling. | 1h 34m long run (steady finish when recovered) | Threshold + speed endurance • Long run with controlled finish | Cutback week |
| 9 | Peak | Train race-specific pacing and fueling. | 1h 58m long run (steady finish when recovered) | Threshold + speed endurance • Long run with controlled finish | — |
| 10 | Peak | Train race-specific pacing and fueling. | 2h 5m long run (steady finish when recovered) | Threshold + speed endurance • Long run with controlled finish | — |
| 11 | Taper | Reduce load; keep rhythm; arrive fresh. | 1h 40m long run (steady finish when recovered) | Short tempo + strides • Easy aerobic + sleep focus | — |
| 12 | Taper | Reduce load; keep rhythm; arrive fresh. | 1h 15m long run (steady finish when recovered) | Short tempo + strides • Easy aerobic + sleep focus | — |
Workout library
The sessions you repeat
You don’t need 50 workouts. You need a small library that you execute consistently, then progress safely.
Easy aerobic run
Purpose: Build volume without accumulating fatigue.
Prescription: 30–60 min at conversational effort. If you can’t talk in full sentences, it’s too hard.
Substitutions
- • Bike or easy elliptical for the same time if impact is an issue.
Red flags
- • Pain that changes your gait.
- • Easy pace drifting harder to hold the same effort.
Strides + drills
Purpose: Improve mechanics and economy without a heavy metabolic cost.
Prescription: After an easy run: 6–10 × 15–20 sec fast-but-relaxed, full walk/jog recovery.
Substitutions
- • 6–8 × 20 sec hill strides for reduced impact.
Red flags
- • Sprint-like intensity that leaves you sore.
- • Tight hamstrings or sharp calf pain.
Tempo / cruise intervals
Purpose: Raise sustainable pace and teach controlled discomfort.
Prescription: 2–4 × 8–12 min at ‘comfortably hard’ with 2–3 min easy between.
Substitutions
- • 20–30 min steady tempo continuous if you pace well.
Red flags
- • Breathing out of control early.
- • Needing to ‘surge’ to hold the last reps.
Interval session (VO₂-ish)
Purpose: Sharpen speed and economy for faster running at a lower cost.
Prescription: 5–8 × 3 min hard with 2–3 min easy; stay controlled, finish with form.
Substitutions
- • 6–10 × 400m on the track with equal jog recovery.
Red flags
- • All-out reps.
- • Form collapse or sharp pains.
Long run (easy with structure)
Purpose: Build durability and rehearsals for race-day pacing and fueling.
Prescription: Mostly easy. When stable: finish the last 15–25 min steady (not a race).
Substitutions
- • Split long run (AM/PM) on high-stress weeks; keep total time similar.
Red flags
- • Long-run pace creeping; next-day fatigue lasting >48h.
- • Fueling causing repeated GI issues (adjust and practice).
Threshold + fast finish
Purpose: Practice the exact intensity you want to execute on race day.
Prescription: 3 × 10 min threshold, then 10–15 min steady finish if you’re recovered.
Substitutions
- • Progression run: easy → steady → controlled hard (only when recovered).
Red flags
- • Needing to ‘push’ early.
- • Shin/calf pain that escalates with pace.
Strength (short + consistent)
Purpose: Support durability and running economy with minimal interference.
Prescription: 2×/week, 20–35 min: hips, calves, hamstrings, trunk. Leave 1–2 reps in the tank.
Substitutions
- • Bodyweight circuit if you’re traveling.
Red flags
- • Heavy DOMS that ruins key sessions.
- • Form breakdown under load.
Adaptation rules
What to do when life happens
Most training failures are not fitness failures — they’re pacing, sleep, or scheduling failures. Use simple rules.
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.
Tools
Numbers to train with
Pick one tool, generate outputs, then plug them into your training week.
Calculator
Running pace + splits
Enter distance and finish time. Get pace per km/mile and a simple splits table.
Same unit as distance.
Pace / km
Pace / mile
Total time
| Split | Distance (km) | Elapsed |
|---|---|---|
| 1 | 5 | 28:26 |
| 2 | 10 | 56:53 |
| 3 | 15 | 1:25:19 |
| 4 | 20 | 1:53:46 |
Assumptions: steady pacing; no terrain/wind adjustments. Use this to plan, then calibrate by effort in real conditions.
Calculator
Race time predictor (Riegel model)
Start with one recent performance, then estimate equivalent 5K / 10K / half marathon / marathon times. Useful for goal-setting and workout planning.
Default 1.06. Higher = more slowdown as distance increases.
Known result
Predicted half
A good checkpoint for endurance readiness.
Predicted marathon
Assumes you train the endurance + fueling required.
| Distance | Predicted time | Pace / km | Pace / mile |
|---|---|---|---|
| 5K | 26:05 | 5:13 | 8:24 |
| 10K | 54:23 | 5:26 | 8:45 |
| Half marathon | 2:00:00 | 5:41 | 9:09 |
| Marathon | 4:10:12 | 5:56 | 9:33 |
This is a simplified model. It does not account for heat, hills, fueling, or whether you’ve trained the durability needed for longer races. Use it for planning — then execute by effort.
Evidence (high level)
Why this structure works
- • Consistency beats hero sessions: durable aerobic volume is the engine.
- • Cutback weeks reduce injury risk and help you absorb training.
- • A small workout library repeated with progression is more effective than endless novelty.
- • Fueling practice is a skill — you train it like pacing.
FAQs
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 sessions per week is a high-ROI habit for durability. Keep it consistent and avoid leaving yourself sore for 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
Half Marathon Training Hub
Half marathon training plans, pacing tools, and guides — structured to reduce overwhelm and keep training simple.
Running Pace Calculator (with Splits)
Convert distance + time into pace per km/mile and generate a splits table. Useful for planning workouts and race pacing.
Race Time Predictor (Riegel Model)
Estimate equivalent 5K/10K/half marathon/marathon times from one known result using a simple model. Useful for goal-setting and pacing.
How to Choose a Marathon Plan (Decision Tree)
A practical decision tree to pick a marathon plan you can actually execute — based on your base, recovery, and constraints.
Sources
- Physical Activity Guidelines for Americans
- Physical Activity
- ACSM guidance and position stands (see journals for specifics)
- Effects of Strength Training on the Physiological Determinants of Middle- and Long-Distance Running Performance: A Systematic Review
- Effects of 16 weeks of pyramidal and polarized training intensity distributions in well-trained endurance runners
- Physical Activity Guidelines for Americans, 2nd edition (PDF)
- Nutrition and Athletic Performance
- Exercise and Fluid Replacement
- Why is hydration important? The effect of dehydration on performance
- Dehydration
- Hyponatremia