Race Training Plan Generator

Building one of these by hand means drawing a grid of weeks and then arguing with yourself about the numbers. People get it wrong in a predictable direction — too much, too soon — because a plan that adds a flat amount each week grows fastest in percentage terms right at the start. This builds the plan from rules instead, and then checks the plan that came out against every one of them.

Race

Weeks until the race

Up to 24. Each race has a sensible minimum.

Kilometres a week now

What you are comfortably running already.

Runs a week

Between 3 and 6.

Most a week may rise, per cent

Ten is the usual rule of thumb.

Most of a week the long run may be, per cent

Between 20 and 50.

12 weeks to a half marathon, peaking at 24.2km a week with a longest run of 8.5km. 234.6km in total.

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun	Total
1	—	4.3	4.3	—	4.3	—	7	20
2	—	4.8	4.8	—	4.8	—	7.7	22
3	—	5.2	5.2	—	5.2	—	8.5	24.2
4 ·easy	—	3.9	3.9	—	3.9	—	6.4	18.2
5	—	4.3	4.3	—	4.3	—	7	20
6	—	4.8	4.8	—	4.8	—	7.7	22
7	—	5.2	5.2	—	5.2	—	8.5	24.2
8 ·easy	—	3.9	3.9	—	3.9	—	6.3	18.1
9	—	4.3	4.3	—	4.3	—	7	19.9
10	—	4.7	4.7	—	4.7	—	7.7	21.9
11 ·taper	—	3.1	3.1	—	3.1	—	5.1	14.5
12 ·taper	—	2.1	2.1	—	2.1	—	3.4	9.7

Distances in kilometres. Sunday is the long run; the intervals and tempo days are the hard ones.

✓ No week goes further than the step above the peak so far — the largest rise over the highest week yet is 10 per cent, against your limit of 10
✓ There are easier weeks to absorb the work — 4 of 12 weeks step back, including the taper
✓ The long run stays a sensible share of the week — at most 35 per cent of a week, against your limit of 35
✓ No two hard days fall together — every hard session has an easy day or a rest day after it
✓ The taper only goes down — the last 2 weeks fall from the peak of 24.2km to 9.7km
✓ Each week's sessions add up to its total — 234.6km over 12 weeks

What this generator does

Grows the weekly distance from where you are now, drops every fourth week back, holds the long run to a share of the week and the race distance, lays the sessions out so no two hard days touch, and tapers the last two weeks.

How to use this tool

Pick the race and how many weeks you have.
Say how far you already run in a comfortable week, and how many days you can run.
Set how fast the plan may build and how much of a week the long run may take.
Read the grid, copy it, and adjust anything that does not suit you.

Understanding the controls

Race: 5 kilometres, 10 kilometres, a half marathon or a marathon. This sets the shortest plan that makes sense and how long the longest run is allowed to be.
Weeks until the race: How long you have. A shorter plan builds from a higher starting point rather than building faster, because the step is capped either way.
Kilometres a week now: What you are comfortably running already, which is where week one starts. Being honest here is the whole point.
Runs a week: Three to six. The layout of hard and easy days changes with it, and is arranged so no two hard days fall together.
Most a week may rise, per cent: The cap on how much further any week may go than the highest week so far. Ten per cent is the usual rule of thumb.
Most of a week the long run may be, per cent: The long run is capped as a share of the week, so it grows with everything else rather than running away from it.

Common use cases

A plan that starts from your current mileage instead of somebody else's
Fitting a build into however many weeks are actually left
Seeing what three, four, five or six running days a week looks like
Working out how much the long run should be at its longest
Understanding why a plan steps back every fourth week

How this generator works

The build grows by your step each week, drops to three quarters every fourth week, and then the taper takes the last two weeks down to sixty and forty per cent of the peak. Distances are kept at full precision throughout and rounded only where they are shown — rounding each session and adding them up moves a week's total by enough to break the very rules the plan is built on. Every rule is then checked against the finished plan: no week goes further than the step above the highest week so far, the long run stays inside its share, no two hard days fall together anywhere in the plan including across the Sunday-to-Monday boundary, the taper only goes down, and each week's sessions add up to the total printed beside them.

Randomness and fairness

Nothing is random. The same settings always build exactly the same plan.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

These are widely used planning conventions, not coaching or medical advice, and no plan can know anything about your health or history.
Paces are described rather than prescribed; the pace calculator works those out from a recent race.
Cross-training, strength work and stretching are not scheduled here.
A plan that starts from a higher weekly distance than you really run is not made safe by any of these checks.

Privacy and your data

The plan is built in your browser from the numbers you type. No distances or settings are transmitted or stored.