The half marathon (21.1 km) is a popular goal: long enough to be a real challenge, short enough to train for alongside work and family. Twelve weeks is a sensible build for a first half if you can already run 10K or about an hour comfortably.
A typical training week
- 2 easy runs of 30 to 50 minutes
- 1 quality session: intervals (e.g. 5 × 4 min) or a tempo run (20 to 35 min comfortably hard)
- 1 long run at easy pace, building gradually
- 2 short strength sessions (see 6 exercises for runners)
- At least 1 rest day
Long-run progression
The long run is the heart of half marathon training. A sample progression, with easier weeks built in:
| Week | Long run | Week | Long run |
|---|---|---|---|
| 1 | 10 km | 7 | 15 km |
| 2 | 11 km | 8 (easier) | 12 km |
| 3 | 12 km | 9 | 16 km |
| 4 (easier) | 10 km | 10 | 18 km |
| 5 | 13 km | 11 (taper) | 13 km |
| 6 | 14 km | 12 (race week) | Race: 21.1 km |
You don’t need to run the full 21.1 km before race day. Long runs of 16 to 18 km prepare most first-timers well.
Practise your fuelling
A first half marathon usually takes somewhere between 1 hour 45 minutes and 3 hours. For efforts that long, taking some carbohydrate during the race can help. Use your long runs to practise: try a gel, a banana or a sports drink every 30 to 45 minutes and see what your stomach tolerates. Read What to eat before, during and after a run.
Pacing on race day
- Get a realistic target from a recent 10K using our race time predictor, then be a little conservative if it’s hot.
- Run the first 5 km at or slightly slower than target pace. Going out too fast is the most common mistake.
- Aim to run the second half at the same pace as the first, or slightly faster.
- Drink at water stations, especially in Kerala’s humidity.
The taper
In the final 10 to 14 days, reduce your running volume while keeping a little race-pace running. You should arrive at the start line feeling fresh and a bit restless. That’s a good sign.
Find your race: half marathons in Kerala.
Frequently asked questions
How many weeks do I need to train for a half marathon?
About 12 weeks is typical for a first half if you can already run 10K comfortably. Newer runners may need longer.
How long should my longest training run be?
For most first-timers, 16 to 18 km is enough. You don't need to run the full distance before race day.
Sources
This article is general information, not medical advice. If you have a health condition, are pregnant, or are returning from injury, talk to a doctor or physiotherapist before starting a new training plan. Read our editorial policy.
Ashkar is a marathoner and Procam Slam achiever, having completed all four Procam International races in a single season. Ashkar writes KeralaRunners’ training guides, combining race experience with published research and guidelines. Health topics are checked against the evidence; see our editorial policy.
