Runsy

12-week marathon training plan for beginners

This free 12-week marathon training plan is built for beginners: three runs a week, a long run that grows from 9.9 to 18 miles, and a peak of 32 miles in weeks 7 and 8 before a three-week taper. Every week is in the table below, in kilometres, with nothing behind a signup.

3

Runs / week

18 mi

Week 1

32 mi

Peak week

18 mi

Longest run

Distances in
12-week beginner marathon plan, distances in km
WeekPhaseSessionsLong runTotal
1base
  • Tueeasy4.3mi
  • Thusteady3.7mi
  • Sunlong run9.9mi
9.9mi18mi
2base
  • Tueeasy5.6mi
  • Thusteady4.3mi
  • Sunlong run12mi
12mi22mi
3base
  • Tueeasy5.6mi
  • Thusteady4.3mi
  • Sunlong run13mi
13mi23mi
4cutback
  • Tueeasy4.3mi
  • Thusteady3.1mi
  • Sunlong run9.3mi
9.3mi17mi
5build
  • Tueeasy6.8mi
  • Thusteady5mi
  • Sunlong run15mi
15mi27mi
6build
  • Tueeasy7.5mi
  • Thusteady5.6mi
  • Sunlong run16mi
16mi29mi
7peak
  • Tueeasy8.1mi
  • Thusteady6.2mi
  • Sunlong run18mi
18mi32mi
8peak
  • Tueeasy8.1mi
  • Thusteady6.2mi
  • Sunlong run18mi
18mi32mi
9taper
  • Tueeasy5.6mi
  • Thueasy4.3mi
  • Sunlong run12mi
12mi22mi
10taper
  • Tueeasy3.1mi
  • Thueasy2.5mi
  • Sunlong run7.5mi
7.5mi13mi
11taper
  • Tueeasy2.5mi
  • Thueasy1.9mi
  • Sunlong run5mi
5mi9.3mi
12race
  • Tueeasy3.1mi
  • Thushakeout1.9mi
  • SunRACE DAY26.2mi
26.2mi31mi

12-week beginner marathon plan, distances in km

Who this plan is for

Beginner here means a first marathon, not a first run. Week 1 is 18 miles over three runs, with a 9.9-mile long run on Sunday, so the plan assumes you already run about 15–18 miles a week and can cover 8.1–9.9 miles at an easy pace without stopping. Most people who fit that description have finished a half marathon or are close to it.

If your longest recent run is under 6.2 miles, do not start here. The 16-week beginner half marathon plan starts at a 6.2-mile long run and builds to 12 miles, which covers the base this plan opens with.

Choose it if race day is 12 to 15 weeks away and week 1 already feels comfortable. It has no spare week: a missed long run late in the build has nowhere to go, so a longer version is safer if you have the time. The other lengths are the 16-week beginner marathon plan and 20-week beginner marathon plan.

The 12 weeks, phase by phase

12 weeks split into two building blocks separated by cutback weeks, two peak weeks, three taper weeks and race week. Every number below is the plan in the table above.

Weeks 1-3, base. Long runs of 9.9, 12 and 13 miles, in weeks of 18, 22 and 23 miles. This is where the routine gets built: every run is easy except one steady effort, and none of it should feel like a test. Easy means you could still speak in full sentences; how to breathe while running explains the talk test.

Week 4, cutback. The long run drops to 9.3 miles from 13 miles and the week to 17 miles. Run it as written. The easier week is where the previous three turn into fitness, and it is the week beginners most often skip.

Weeks 5-6, build. Long runs of 15 and 16 miles, in weeks of 27 and 29 miles. The long run carries the progression; the weekday runs grow in proportion to it.

Weeks 7-8, peak. The hardest stretch of the plan: two weeks at 32 miles, each with a 18-mile long run. If a fortnight in your calendar cannot absorb that, this is the one to protect.

Weeks 9-11, taper. Volume comes down to 22, 13 and 9.3 miles and the long run to 12, 7.5 and 5 miles. You keep the frequency and lose the fatigue; fitness does not fade in two or three weeks, tiredness does.

Week 12, race week. Tue 3.1 miles easy and Thu 1.9 miles shakeout, then the race on Sunday. That is all the running in the six days before the start line.

12, 16 and 20 weeks: how the lengths differ

PlanWeek 1Longest runPeak weekLong runs of 16 miles+Biggest long-run stepCutback weeksTotal
12 weeks (this plan)18 miles18 miles (week 7)32 miles3+1.9 miles1275 miles
16 weeks18 miles18 miles (week 11)32 miles4+1.2 miles2367 miles
20 weeks18 miles18 miles (week 15)32 miles5+1.2 miles3459 miles

Every length starts from the same 18 miles week 1 and reaches the same 32 miles peak week and 18-mile long run. The length decides how gradually you get there, not where you end up: the 12-week plan reaches its longest run in week 7, the 20-week plan in week 15, with 3 cutback weeks instead of 1.

This plan's 275 miles is about 10 times the race distance, roughly 50 hours of easy running at 6:30 to 7:00 per kilometre. How long is a marathon breaks down what that time costs week by week.

How the plan is built

Cutback weeks. Week 4 drops the long run to 9.3 miles, about 70% of the last full week's. Adaptation happens in the easier week, not the hard one.

Steps are capped at 20%. No long run is more than a fifth longer than the last full week's. The biggest single step in this plan is +1.9 miles, from week 1 to week 2. Where a shorter plan cannot reach the usual peak inside that limit, it settles for a lower peak instead of taking an unsafe step.

A real taper. The three weeks before race week come down to 22, 13 and 9.3 miles, and race week carries 5 miles of running before the start line.

Pace comes from your goal. The table gives distances, not paces: if you are aiming for a time, 5-hour marathon pace is 11:27 per mile and 4-hour marathon pace is 9:09.

When is your race?

Your plan · free preview

12-week marathon plan

Beginner · 3 runs a week

Starts next Monday

Level

Length

Week 1Race week
Longest run
18mi
Biggest week
32mi
Whole plan
275mi

Train for this in Runsy

$12.99/mo or $79.99/yr after a free first week. iPhone and iPad.

The app builds your own plan when you set it up; this preview is a guide.

Download on theApp Store
Week by week · 12 weeks · in miles
12-week marathon plan, week by week
WeekPhaseSessionsTotal
1base
  • Tueeasy4.3mi
  • Thusteady3.7mi
  • Sunlong run9.9mi
18mi
2base
  • Tueeasy5.6mi
  • Thusteady4.3mi
  • Sunlong run12mi
22mi
3base
  • Tueeasy5.6mi
  • Thusteady4.3mi
  • Sunlong run13mi
23mi
4cutback
  • Tueeasy4.3mi
  • Thusteady3.1mi
  • Sunlong run9.3mi
17mi
5build
  • Tueeasy6.8mi
  • Thusteady5mi
  • Sunlong run15mi
27mi
6build
  • Tueeasy7.5mi
  • Thusteady5.6mi
  • Sunlong run16mi
29mi
7peak
  • Tueeasy8.1mi
  • Thusteady6.2mi
  • Sunlong run18mi
32mi
8peak
  • Tueeasy8.1mi
  • Thusteady6.2mi
  • Sunlong run18mi
32mi
9taper
  • Tueeasy5.6mi
  • Thueasy4.3mi
  • Sunlong run12mi
22mi
10taper
  • Tueeasy3.1mi
  • Thueasy2.5mi
  • Sunlong run7.5mi
13mi
11taper
  • Tueeasy2.5mi
  • Thueasy1.9mi
  • Sunlong run5mi
9.3mi
12race
  • Tueeasy3.1mi
  • Thushakeout1.9mi
  • SunRACE DAY26.2mi
31mi

Every plan here, but it adapts.

Runsy rebuilds your week around the runs you actually did.

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Free training plansCalculators

$12.99/mo or $79.99/yr after a free first weekiPhone and iPad

$12.99/mo or $79.99/yr after a free first weekiPhone and iPad

Fair questions

How many miles a week is this marathon plan?

It starts at 18 miles in week 1 and peaks at 32 miles in weeks 7 and 8. Across all 12 weeks it adds up to about 275 miles, an average of 23 miles a week.

What is the longest run in a 12-week marathon plan?

18 miles, run twice, in weeks 7 and 8. The plan stops 8.2 miles short of race distance on purpose: past roughly 19 miles the recovery cost outgrows the aerobic return for most amateur runners, and the last stretch on race day comes from the weekly volume and the taper.

Is 12 weeks enough to train for a marathon?

Yes, if week 1 (18 miles with a 9.9-mile long run) is comfortable for you today. If it is not, the 20-week version is the more forgiving choice: it starts from the same place but climbs in steps of at most 1.2 miles and has 3 cutback weeks to absorb a missed week.

Can I prepare for a marathon in 3 months?

Twelve weeks is about three months, and this plan does it, but only from an existing base: it opens with a 9.9-mile long run and reaches 18 miles by week 7. From a lower base, three months is better spent on a half marathon.

Is this plan free?

Yes. Every week is on this page, with no signup or download. The subscription is for the app, which rebuilds the plan around the runs you actually complete.

This plan, rebuilt around your week

$12.99/mo or $79.99/yr · week 1 free

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