QUICK ANSWER
This half marathon training plan is an example that uses 3–4 runs a week over 12 weeks. Marathon plans often run 12 to 20 weeks, depending on fitness. A good guide to effort is that you can talk in short sentences but not sing. Build slowly, and see a doctor first if you have heart disease or chest pain on effort.
Key takeaways
- Three or four runs a week can fit around a full-time job.
- Keep most runs easy, and add distance a little at a time.
- In heat, humidity or haze, slow down or move indoors rather than skipping the week.
- Track runs completed, your long run and how easy runs feel.
- If you can talk in short sentences but can’t sing, you’re at a moderate effort.
At a glance
12-week half marathon training plan: a 3–4 run week at a glance
| Phase | Weeks | Runs per week | Easy runs | Long run | Focus |
|---|---|---|---|---|---|
| Start | 1–4 | 3 | 2, at a comfortable effort | Short, lengthen slightly | Build the habit |
| Build | 5–8 | 3–4 | 2–3, at a comfortable effort | Longer every week or two | Add a fourth run or one steady effort, not both |
| Peak | 9–11 | 3–4 | Keep easy | Longest of the plan, then hold | Stay consistent |
| Taper and race | 12 | 2–3 | Short and easy | Reduced | Rest before race day |
Half marathon training plan: what does a 3–4 run week look like?
Marathon plans often run 12 to 20 weeks, depending on fitness [1]. For general health, Singapore’s guidelines suggest adults do 150 to 300 minutes of moderate activity a week. This is a general guide, not a half marathon training time [1].
One way to lay out a week in this plan is:
- Two or three easy runs on weekdays, early or after work.
- One long run at the weekend.
- An optional fourth run once the base feels comfortable.
Distances are left out on purpose. Set the long run to what feels manageable for you.
What is easy run pace and how do I find it?
Being able to talk in short sentences but not sing marks moderate effort [2]. It is not a test made for easy running pace, but it is a handy guide to effort. If you can’t talk, slow down.
Try chatting to a running partner, or reciting a few song lines, partway through a run. If it comes out in gasps, ease off. Beginners are advised to start small and slow, then build up over time [2].
Why this varies from person to person
Your easy pace depends on your own fitness, so it won’t match a friend’s. Go by effort, not a number copied from someone else.
How do I build weekly distance without getting injured?
Add distance gradually. A common guide is to raise weekly distance by no more than 10% a week [1]. The evidence linking distance changes to injury is mixed, so treat it as a guide [3].
In new runners, harder running in the previous week was linked to more injuries [4]. Harder running was linked to more injuries, though this does not prove that keeping runs easy prevents them [4].
A few habits help:
- Change one thing at a time: distance, speed or number of runs.
- Build frequency and intensity gradually [5].
Around 1 in 7 new runners and 1 in 4 recreational runners picks up an injury [3].
What should I change if it is hot, humid or hazy?
In Singapore’s heat, go by effort, not pace. Slow down until you can still talk [2].
Try these adjustments:
- Run early in the morning or later in the evening, away from the hottest hours.
- Move to a treadmill when the haze is bad.
- Shorten the run instead of skipping it, and carry water.
If you feel dizzy or unwell, stop.
Who should see a doctor before hard training?
Anyone with heart disease, high blood pressure or diabetes should see a doctor before hard training. So should anyone with chest pain or breathlessness on effort, or a family history of early heart disease.
The Health Promotion Board’s Fitness Tracker app includes a short questionnaire (PAR-Q) that helps show whether you should check with a doctor first [6]. Your polyclinic or GP can advise.
How do I track progress and know I’m on track?
Track three things: runs completed, the length of your long run and how easy runs feel.
The Health Promotion Board’s aerobic fitness score is based on a 2.4 km run, which can be used to track fitness [6].
Fuelling around your runs
Before a morning run, try a banana or a slice of toast. After the long run, chicken rice or fish soup with rice is a lighter choice than fried noodles.
Fitting runs around a busy week
Two weekday easy runs and a weekend long run suit many office schedules. If a Tuesday client call overruns to 8 pm, move that run to Wednesday morning instead of doubling up later in the week.
Fiya can fit each week’s runs around your calendar and check in on WhatsApp, so a missed day doesn’t unravel the plan.
Your 12-week half marathon build, one stage at a time
- Weeks 1–2: run three times a week at a comfortable effort, and change nothing else.
- Weeks 3–4: lengthen the weekend long run slightly.
- Weeks 5–8: try adding a fourth run or one steady effort, not both.
- Weeks 9–11: hold your longest long run and keep the other runs easy.
- Week 12: cut distance, rest well and race.
When to see a doctor
- Chest pain or pressure when running: stop and seek urgent care
- Fainting or dizziness during or after a run
- Unusual breathlessness on effort
- Pain that worsens or changes how you run
HOW FIYA HELPS
Keeping the runs going
The plan is the easy part. Keeping three or four runs alive through a regional trip or a late week is harder. Fiya, Fyxlife’s personal health manager, works over WhatsApp and fits your runs around the week you’re actually having. Its plans are reviewed by Fyxlife’s expert team, and Fyxlife sells nothing.
Frequently asked questions
Skip it and carry on with the next planned run. Don’t squeeze in extra runs to catch up. Raising frequency and intensity gradually is the sensible approach, and harder weeks were linked to more injuries in new runners.
We don’t have a set length for half marathon training. Marathon plans often run 12 to 20 weeks, depending on fitness. If you are starting from little running, allow extra time rather than rushing the long run.
A good time is personal. Finishing a half marathon comfortably is a strong first result. After that, compare your own times from race to race.
Related reading
- Marathon training plan: 16 weeks for busy professionals
- NEAT Explained: Why Everyday Movement Matters
- HIIT Protocol for Longevity Athletes: The Right Way
- Strength Training for Women: The Evidence-Based Protocol
References
- Marathon Training: How to Prepare, Cleveland Clinic, 2023
- How Much Exercise Is Enough for a Healthier You, HealthHub (Health Promotion Board), 2023
- Association Between Running Injuries and Training Parameters, Journal of athletic training, 2022
- NLstart2run study, Journal of science and medicine in sport, 2016
- Aim for at least 150 Minutes of Physical Activity Every Week, HealthHub (Health Promotion Board), 2026
- Health Promotion Board Launches National Physical Activity Guidelines, Health Promotion Board, 2026
Sources checked on 2026-10-17.
This article is general information, not medical advice. Talk to your doctor about your own results and before changing any medicine.
