Runners spread across a city avenue during a marathon

The Big Half

0975 km half marathon staged in London by London Marathon Events.

Prepare for The Big Half

A plan built from your answers and your race date.

half marathon training plan

The Big Half is run in London, on a road course linking several neighbourhoods in the east of the capital. The setting is that of a major British city race: tarmac, river crossings, residential streets and street entertainment along the way. The roads are closed to traffic, so you run on clear tarmac from the first kilometre to the last.

0975 km. Its purpose is as much community-focused as competitive: it draws club runners chasing a time alongside participants entering through charities and local community groups.

The formats

One format only.

Format	Distance
Semi-marathon	13.1 mi

Organizer information, checked on September 21, 2026 · londonmarathonevents.co.uk

When to start

A build for this distance usually runs 10 to 16 weeks. Counted back from race day, that puts the start somewhere between May 10, 2027 and June 21, 2027.

These ranges are working conventions, not a research finding — no trial has compared plan lengths against each other. What matters more is that the plan was built for the weeks you actually have, rather than shrunk down from a longer one.

How to choose your start date

When to start

May 10, 2027

→ June 21, 2027

Worth reading before you enter

Races and distances 10K, half, marathon: what each one really asks They are all running. They are not the same event. What limits you, how long you need, and how the race falls apart — all three change with the distance. Read Races and distances The big marathons: what each one actually demands A marathon is 42.195 km everywhere. What changes is the profile, the crowd, the weather you are likely to get — and so what your training should emphasise. Read Training Eating and drinking: what’s proven, what isn’t This is where confident advice most often runs ahead of the evidence. Some of it is well tested. Some is opinion wearing a number. And one common habit can kill you. Read

Questions

What is the date of The Big Half in 2027?

The Big Half is run on Sunday, September 5, 2027 in London. Date published by the organizer, checked on September 21, 2026.

How long is The Big Half?

0975 km. The course is entirely on road and through the city, with no trail sections or technical ground to deal with.

How do I enter The Big Half 2027?

Entries open on the London Marathon Events website. Additional bibs are made available through partner charities, which allocate places in return for a fundraising commitment towards their cause.

Other races

This list keeps growing; it draws no line. A race that is missing is prepared for in exactly the same way.

Bath · United KingdomHalf marathon GetPRO Bath Half Marathon Mar 14 1 km half marathon run through the streets of central Bath, England. Reading · United KingdomHalf marathon Green Park Reading Half Marathon Mar 21 A Mini Marathon runs alongside it for younger participants on the same day. London · United KingdomHalf marathon London Landmarks Half Marathon Apr 4 0975km route strings together the capital's best-known landmarks on roads shut to traffic. Your race is not here? Tell us about your race You can prepare for it all the same. Any race, anywhere, and even a goal without a race.

Your race is on the calendar. Your plan should be too.

Build my plan

Secure payment with Stripe. Then allow about 30 minutes for your profile, in several sittings if you like.