Your first half marathon: a 12-week plan for recreational runners

If you can already run eight to ten kilometres without stopping and you are wondering whether 21.1 kilometres is realistic in three months, it is. The race itself is rarely what goes wrong with a first half marathon — what goes wrong is week seven, when a calf or an Achilles gives up because the mileage climbed too fast. This plan is written for someone training three or four times a week with nobody around to tell them to ease off.

What you need before week one

Twelve weeks is not a plan from nothing. It is a plan from a decent base to a finish line. A base means you have been running three times a week for a month or two, 20 to 25 kilometres in total, with a longest run somewhere between eight and ten kilometres.

If you are below that, do not compress the plan — add four to six weeks of easy running first. The same goes if you are coming back after a long gap, in which case a structured six-week return to training will serve you better than any race programme.

Kit-wise you need one pair of shoes that still feels fine at kilometre ten. Running shoes are usually replaced somewhere between 500 and 800 kilometres, depending on your weight and the surfaces you run on.

What a training week looks like

Four runs a week suits most recreational runners: two easy, one quality session, one long run. If you can only manage three, drop an easy run — never the long one.

A rough split that holds up well in practice: roughly 80 per cent of your weekly kilometres should be easy, the rest faster. Easy means you can speak in full sentences while running. If you cannot, you are running moderately hard, which is the pace that costs the most and gives back the least.

• Monday — rest, or 30–40 minutes walking, cycling or swimming
• Tuesday — easy 5–7 km
• Wednesday — quality session (tempo or intervals)
• Thursday — rest or 30 minutes of strength work
• Friday — easy 5–6 km
• Saturday — rest
• Sunday — long run

Two half-hour strength sessions a week are worth more than a fourth easy run. Squats, lunges, press-ups, hip bridges and calf raises, two or three sets of 8 to 12 reps each. If your squat technique is shaky, sort that out before you add load.

The 12-week plan

Weeks 1–4: building the habit

Total volume of 25 to 32 kilometres a week. The long run goes 10, 12, 13 and then 9 kilometres — the fourth week is deliberately shorter, and that cutback is not optional. The quality session stays modest here: six repetitions of 20 seconds at a brisk pace at the end of an easy run, with full recovery between.

Weeks 5–8: the mileage arrives

Total volume of 33 to 42 kilometres. Long runs of 14, 16, 11 and 17 kilometres. The quality session gets more serious — 20 to 30 minutes at a comfortably hard tempo, or five to six repetitions of three minutes fast with two minutes of jogging in between. This is where most people overreach. If your legs have not recovered from Wednesday by Friday, cut back rather than push on. Interval work has its own rules, and racing over 800 and 1500 metres shows clearly why nobody runs them every day.

Weeks 9–10: the peak

Total volume of 42 to 48 kilometres, with long runs of 18 and 14 kilometres. Put four or five kilometres at your intended race pace into one long run, and put them at the end, when your legs are already tired. That is the single most useful half hour in the whole block.

Weeks 11–12: the taper

Cut total volume by about 30 per cent in week eleven and about 50 per cent in week twelve, but keep a little speed — three or four one-minute pickups keep the legs awake. The last long run is 10 kilometres, eight or nine days out. In the final week you cannot gain anything, but you can lose everything, so this is not the moment to make up for missed sessions.

Pacing, food and fluid

Anything over 75 minutes needs fuel: 30 to 60 grams of carbohydrate an hour, whether that comes from a gel, a banana or a sports drink. Fluid runs roughly 400 to 800 millilitres an hour in heat, less when it is cool. Practise all of it in training — nothing new on race day, not the gel, not the shoes, not the breakfast.

On the day, run the first five kilometres 10 to 15 seconds per kilometre slower than your target. It will feel far too slow, and that is exactly right. A half marathon is lost in the first twenty minutes and won in the last five kilometres.

The mistakes that cost most

The first is turning every long run into a fitness test. A long run is an easy run that lasts a long time, nothing more.

The second is skipping cutback weeks because you feel good. You feel good precisely because the plan is working.

The third is running through pain that lasts more than two or three days and gets worse as the run goes on. Knee pain is the most common complaint among runners and has more possible causes than people assume. If your sleep, appetite and motivation drop at the same time, check the signs of overtraining before adding another session.

When to see a doctor

Get checked before you start if you are over 40 and have been largely inactive, if you have a known heart or blood pressure problem, or if there is a history of early cardiac events in your family.

Stop and seek medical advice for chest pain or tightness, fainting or dizziness, breathlessness out of proportion to the effort, or sharp pinpoint pain on a bone that hurts when you press it with a finger — that last one needs assessment, not two days off.

The short version

• Start from a base of 20–25 km a week with a long run of 8–10 km; if you are below that, build the base first.
• Four runs a week: two easy, one quality, one long, with roughly 80 per cent of the kilometres easy.
• The long run builds to 18 km around week nine, with a cutback week every fourth week.
• Past 75 minutes, take 30–60 g of carbohydrate an hour and rehearse it in training, never on race day.
• Taper by 30 then 50 per cent over the last two weeks — nothing is gained there, but plenty can be lost.