20-Week London Marathon Training Plan

London, United KingdomApril 25, 2027

Start around December 6, 2026. The calendar below gives each phase a real date, then the course guidance shows where to make the build specific to London Marathon.

London is the hardest major to get into and one of the easiest to love: a fast, flat, point-to-point course from Greenwich to The Mall, lined shoulder-to-shoulder with what might be the best crowds in the sport, past Cutty Sark, over Tower Bridge, and down the Embankment to Buckingham Palace.

Race day
April 25, 2027
Start window
December 6, 2026
Runway
20 weeks
Course
Greenwich to The Mall
Plan choice
Current training

Does this window fit your starting point?

Use the longer window to make the early build calmer, not to add five months of hard training. The plan should begin close to your current load, hold most running easy, and delay the biggest race-specific work until the middle of the cycle.

  • You want a longer foundation phase before marathon-specific training.
  • Your current mileage is steady but below the load you expect to carry later.
  • You prefer gradual long-run growth with regular step-back weeks.
  • You can sustain a five-month routine without turning every week into a peak week.

The 20-week London Marathon calendar

These dates define the job of each phase. Your current mileage, recent longest run, experience, goal, and available days still decide the actual workouts inside them.

Foundation

Weeks 1–6

Dec 7, 2026–Jan 17, 2027

Set the routine, grow easy volume gradually, and finish each week with enough control to repeat it.

Build

Weeks 7–13

Jan 18, 2027–Mar 7, 2027

Extend the long run, introduce race-specific terrain, and keep recovery weeks on the calendar.

Peak

Weeks 14–17

Mar 8, 2027–Apr 4, 2027

Complete the most demanding race rehearsals and settle fueling, pacing, shoes, and clothing before taper begins.

Taper

Weeks 18–20

Apr 5, 2027–Apr 25, 2027

Reduce the load, keep familiar running in the week, and let the work from the previous four months show up on race day.

Make the window specific to London Marathon.

Build general durability first. Add the race's hills, flat sustained running, downhill exposure, heat, or humidity in layers after the weekly rhythm is stable, then make the final long runs the most course-specific.

Read the full race guide

How to train for London

Train it like the fast course it is: sustained goal-pace segments in long runs, even-split discipline, and a plan for the early downhill miles: the Greenwich descent plus race-day adrenaline is London's classic too-fast start. Practice opening long runs controlled.

A late-April race means a winter buildup with the biggest weeks in February and March. British runners know this dance; everyone else should plan for cold, dark long runs and trust the spring taper. And rehearse crowd discipline: with support this loud for this long, running your own pace amid noise is a genuine skill worth practicing in race-crowded training events.

Let your current training decide the actual plan.

Current mileage, recent longest run, marathon experience, goal, and available days determine which plans rank first. After you choose and subscribe, Stride dates every workout through April 25, 2027.

Build My Plan

20-week London Marathon plan questions, answered.

When should I start a 20-week London Marathon plan?

The 2027 London Marathon is scheduled for April 25, 2027, so the 20-week window opens around December 6, 2026. Treat that as the outside edge of the window, then line week one up with the plan's normal weekly rhythm.

Is a 20-week plan long enough for the London Marathon?

Use the longer window to make the early build calmer, not to add five months of hard training. The plan should begin close to your current load, hold most running easy, and delay the biggest race-specific work until the middle of the cycle. The course does not change the opening load you can handle, so choose from your current mileage and recent longest run before adding race-specific terrain.

How should I prepare for the London Marathon course in 20 weeks?

Build general durability first. Add the race's hills, flat sustained running, downhill exposure, heat, or humidity in layers after the weekly rhythm is stable, then make the final long runs the most course-specific. Train it like the fast course it is: sustained goal-pace segments in long runs, even-split discipline, and a plan for the early downhill miles: the Greenwich descent plus race-day adrenaline is London's classic too-fast start. Practice opening long runs controlled.

What if the 20-week London Marathon window has already started?

Do not double weeks or cram missed mileage into the remaining calendar. Use your current mileage, recent longest run, experience, goal, and available days to choose a plan that can enter at an appropriate point while preserving the taper.

How long do I need to train for the London Marathon?

Most Stride marathon plans run 12 to 20 weeks, putting the heart of a London buildup in the winter months. Get matched in the app and Stride maps every week from today to The Mall.

How do I get into the London Marathon?

The public ballot (heavily oversubscribed), Good For Age qualifying times, championship entry for club runners, or a charity place with a fundraising commitment. Most first-time Londoners get in via charity or years of ballot persistence.

Put the 20-week window against your actual race.

Each page counts back from race day, maps the 4 phases to real dates, and applies the window to that course and its typical conditions.