12-week half marathon training plan that survives real life

Most half marathon plans are written for someone with no job, perfect sleep and no interest in lifting. They are correct and they are useless. Here is the structure that works, the week-by-week numbers, and the rules that let it bend without breaking.

How long does it take to train for a half marathon?

Twelve weeks is the standard answer for someone who can already run 8 to 10 km comfortably, and it is a good one. It leaves room for three blocks of four weeks, a down week in each, a real taper, and one disrupted week without having to compress anything. Sixteen weeks gives more margin for beginners; eight is possible for a regular runner who wants to finish rather than race.

What matters more than the number of weeks is the ramp inside them. A twelve-week plan that climbs too fast is worse than a ten-week one that climbs sensibly.

What does a 12-week half marathon plan look like?

Three blocks of four weeks: base, build, and sharpen, with a taper inside the last block. Within each block, three weeks climb and the fourth drops volume by about a third. The long run grows from roughly 10 km to 18 or 19 km; one quality session a week (tempo in the base block, threshold intervals in the build, race-pace work in the sharpen) sits mid-week, and everything else is easy. Genuinely easy: conversational, in your lowest two heart-rate zones.

The volumes are for someone starting around 20 to 25 km a week. Scale them to your own start point and keep the shape; the shape is the plan.

PeakU does this from your own data. A coach that reads everything you already track. Join the free beta →

Which rules matter more than the sessions?

• Ramp rate. Weekly volume rises no more than about ten percent, and the long run no more than 2 km at a time.
• Hard-day spacing. At least 48 hours between the long run and the quality session; a heavy lower-body lift counts as a hard day.
• Down weeks are not optional. The fourth week is where the adaptation lands.
• Taper for real. Volume drops 40 to 50 percent in the last ten days; intensity stays.
• Easy means easy. If the easy runs drift into the middle zones, the quality session suffers and the ramp stops being safe.

The ramp rule exists because tendons and bone adapt more slowly than your heart and lungs. The review evidence on load changes and running injury is mixed on exact figures, but the direction, that rapid increases are the risk, holds. The detail is in how much training load is too much.

How do you fit a half marathon plan around work and travel?

Travel Thursday? The long run moves to Saturday and the quality session to Tuesday; nothing else changes. Two short nights? Cap the quality session at two thirds and keep the rest. Heavy leg day landed on Wednesday? The tempo waits until Friday. The plan is a set of constraints, not a calendar, and the sessions can slide as long as the constraints hold.

Write the week as rules and most disruptions become rescheduling rather than failure. The same approach at a shorter distance is in the 10K plan built for a week that keeps changing; the rules are the same, the numbers smaller.

1. Protect the long run first. If the week collapses to two runs, it is one of them.
2. Move the quality session to any day 48 hours from the long run and from heavy lifting.
3. Shorten easy runs rather than skipping them, and never make them harder to compensate.
4. If you lose a whole week, resume at the volume you left and drop one climbing week from the block. Do not make it up.

Can you lift during half marathon training?

Yes, and you should: strength work supports running economy and injury resilience, which is the point of lifting during a running block. The cost is real but small, and it is specific to running rather than aerobic work in general. Two heavy, low-volume sessions a week hold what you have; trying to add muscle during the build is the fight you lose.

Count every heavy lower-body session as a hard day under the 48-hour rule and never put one the day before the long run. The evidence on the interference effect and the exact weekly arrangement is in strength training while training for a half marathon.

How easy should easy runs be?

Easier than feels productive. The large majority of the week's kilometres should be run at a pace where full sentences are comfortable, in the lowest two heart-rate zones. The quality session only works if you arrive at it fresh, and the ramp is only safe if the easy days are actually recovery.

Most self-coached runners run their easy days a zone too hard and their hard days a zone too easy, and end up with a lot of tiring middle. If you have never trained by zones, the zone 2 beginner's guide is the place to start.

What should race week look like?

Short, familiar and slightly boring. Volume is down 40 to 50 percent from the peak, but you keep touching race pace in small doses so your legs remember it: a few kilometres mid-week, a handful of strides two days out. Nothing new. Not new shoes, not a new breakfast, not a new stretching routine from a video.

• Monday to Wednesday: easy runs of 30 to 40 minutes, one with 3 × 2 km at race pace.
• Thursday: easy 25 minutes or rest.
• Friday: 20 minutes easy with four or five strides.
• Saturday: rest, or 15 minutes of walking to stay loose.
• Sunday: race, starting a touch slower than goal pace for the first two kilometres.

Expect to feel flat and restless mid-week; that is the taper working, not fitness leaving. Sleep is the training in race week, and the night two before the race matters more than the night before, which is often poor whatever you do.

Letting a coach hold the constraints

PeakU builds the block toward your race date, audits it for ramp rate and hard-day spacing before it shows you anything, reflows the week when readiness drops or a session slips, and predicts your finish from the training you did. Because it reads your lifting from Hevy, it knows Wednesday's squats were a hard day without being told. When it refuses a plan, it tells you which rule it would have broken.

Hen Eytan · Founder, UPeak

Builds the UPeak apps and writes up the research behind them.