Do you need running experience before starting half marathon training?
You should be able to run 5 km continuously before beginning a 12-week half marathon plan. This doesn't mean you need to be fast — it means your body has adapted to the basic stress of running and is ready to handle a structured load increase.
If you can't yet run 5 km without stopping, spend 4–6 weeks on a couch-to-5 km programme first. This is not a delay — it's the foundation that prevents the most common beginner injuries (shin splints, IT band syndrome, knee pain) that occur when runners increase volume too fast.
If you can already run 5–7 km comfortably, you're ready. You don't need to be able to run 10 km. You don't need a recent race under your belt. You need consistent easy running and the ability to add mileage without breaking down.
How long does it take to train for a half marathon as a beginner?
12 weeks is the standard. It gives you enough time to build from your 5 km base to a long run of 18–20 km without compressing the load into a dangerous ramp rate. Below 10 weeks, the risk of injury rises significantly.
If you have 16 weeks before your race, don't start the formal 12-week plan immediately. Use the first 4 weeks to build your easy run base — three runs a week at conversational pace, slowly extending the long run from 7 to 10 km. Then begin week 1 of the plan with more aerobic fitness behind you.
Don't try to compress the plan into fewer weeks by running harder or adding extra sessions. The adaptations in a half marathon plan — increased mitochondrial density, improved fat utilisation, stronger connective tissue — take time that can't be rushed by intensity.
What pace should a beginner run in training?
Most of your training — roughly 80% — should be at easy pace. Easy means conversational: you can speak full sentences without gasping. If you can't, you're running too fast.
Most beginner runners run their easy runs too fast. This is the single most common training mistake. Running too hard on easy days means you arrive at your one quality session per week (tempo or intervals) already fatigued, and you can't hit the effort that session actually requires.
For a runner targeting a 2:15–2:30 finish, easy pace is typically 7:00–8:00 min/km (11:15–12:50 min/mi). Yes, that slow. Yes, it works. The aerobic engine being trained at that pace is the same one that powers you through kilometres 15–21.
- →Easy runs: conversational pace — could speak a full sentence without pausing
- →Tempo runs: comfortably hard — can say a few words but not a full sentence
- →Long runs: easy pace throughout, even if that means slowing down
- →Race pace: slightly faster than easy, slightly slower than tempo — only in later weeks
What is a realistic half marathon time for a beginner?
Most first-time half marathon runners finish between 2:10 and 2:45. If you can run 5 km in 30–35 minutes, a 2:15–2:30 finish is realistic on a structured 12-week plan. If your 5 km is 35–40 minutes, 2:30–2:50 is more appropriate.
Don't set a time goal in your first race that requires running faster than your training suggests. The goal for a first half marathon should be to finish feeling controlled — not to hit a specific number at the cost of blowing up after km 16.
A useful predictor: multiply your comfortable 10 km time by 2.2. That gives you a rough estimate of your half marathon capability. If you haven't run a 10 km, multiply your 5 km time by 4.6. These are estimates — actual race day performance depends on pacing, weather, and course.
What does a beginner half marathon training week look like?
A standard beginner week in the base phase includes three to four runs: one long run (the most important session of the week), one easy run, and one quality session (tempo or light fartlek). Rest days are not optional — they are when your body adapts to the training.
The long run is sacrosanct. If you can only get out three times in a week, the long run is the first session to protect. It is the single session most predictive of your race day finish time.
Don't be surprised when your long run feels genuinely difficult. That's appropriate. The psychological adaptation — learning to stay relaxed while uncomfortable — is as important as the physiological one.
- →Monday: rest or easy 5 km shakeout
- →Tuesday: easy 6–8 km
- →Wednesday: rest
- →Thursday: quality session (tempo 6–8 km or easy fartlek)
- →Friday: rest
- →Saturday: long run (building from 10 to 18 km over 12 weeks)
- →Sunday: rest or 5 km easy
How do you avoid injury in your first half marathon training block?
Follow the 10% rule: never increase your total weekly mileage by more than 10% from the previous week. This single guideline prevents the majority of overuse injuries in amateur runners.
Include a recovery week every third or fourth week where total mileage drops by 20–30%. Your body does not adapt during the hard weeks — it adapts during the easier ones. Runners who skip recovery weeks plateau or get injured.
Run easy runs genuinely easy. Most beginner injuries come not from the long run but from running the easy runs too hard and arriving at harder sessions already fatigued. If your easy run heart rate is above 75% of max, you're running too fast.