How Long Does It Take to Train for the London Marathon?

How long does it take to train for the London Marathon?

Most runners need about 16 to 20 weeks to train for the London Marathon if they can already run a little, and longer if starting from scratch. A complete beginner is better allowing six months or more to build up safely. With the 2027 race on 24 and 25 April, that means beginning your build in the winter, around December 2026 or January 2027.

The reason for that range is simple. A marathon is 26.2 miles, and your body needs time to adapt to steadily longer runs without picking up an injury. The people who reach the start line feeling ready are usually the ones who built up gradually, not the ones who crammed. Think of the timeline as a general guide rather than a fixed rule, because fitness, age, past injuries and how much time you can give to running all shift the picture.

A common structure is a few weeks of base building, then a main block of 16 to 20 weeks where your long run grows week by week, followed by a two to three week taper where you ease off so you arrive fresh. If any pain, injury or health concern comes up along the way, it is always worth seeing a qualified professional before pushing on.

How long if you are a beginner?

If you are brand new to running, give yourself six months or more, and ideally closer to nine months to a year, to reach the London Marathon comfortably. That may sound like a lot, but building from your very first jog to 26.2 miles is a big jump, and rushing it is the fastest way to end up sore or sidelined.

A sensible path for a beginner is to spend the first couple of months just getting comfortable running for 20 to 30 minutes, often using a run and walk approach. Once you can jog for half an hour without stopping, you have a base to start a proper marathon block. For the 2027 race, a true beginner would want to begin that early groundwork in the second half of 2026, so there is no scramble once winter arrives.

Go gently, keep most runs at an easy, chatty effort, and build your weekly distance slowly. Slow and steady really does win here.

How long if you can already run 10k or a half marathon?

If you can already run 10k, a standard 16 to 20 week marathon block suits you well. You have a running base, so the job is mostly extending your long run and getting used to more time on your feet. Starting your build around December 2026 or January 2027 lines you up nicely for the April race.

If you have finished a half marathon, you are in a strong position and can often work to the shorter end of that range, roughly 14 to 16 weeks, because your body already handles longer runs. Regular runners with a few races behind them may need even less. The key is not to shorten things so much that your long runs jump up too quickly, since that is where injuries tend to creep in.

How many days a week should you run?

For most first-time marathoners, three or four runs a week is plenty. A simple weekly shape is one long run, one steadier or slightly faster run, and one or two easy runs, with rest days in between. Beginners often do well on three runs a week so the body has more time to recover.

More experienced runners might run five days a week, but more is not automatically better. Rest days are when your body actually gets stronger, and a little strength and mobility work helps your legs cope with the mileage. The best plan is the one you can stick to around work, family and life, so pick a number of days you can genuinely commit to across the whole block.

When should you start training for the 2027 race?

The 2027 TCS London Marathon is a two-day event, taking place on Saturday 24 and Sunday 25 April 2027. It is set to be the biggest ever, with 100,000 places on offer, and it drew a record 1,338,544 ballot applications. The course runs from Greenwich to Westminster and is famously flat and fast, which makes it a wonderful first marathon.

Working back from late April, a 16 to 20 week build means most runners will start in December 2026 or January 2027. If you are newer to running, count back six months or more and begin your easy base building in the second half of 2026, so you reach winter already able to jog for half an hour. Winter training in the UK can be cold and dark, so plan for kit, safe routes and a bit of flexibility when the weather turns.

For the latest details on entry, the ballot, charity places and event logistics, always check the official London Marathon website, since those specifics can change year to year.

How Edge helps you build for London 2027

Edge gives you a fully personalised training plan, ready within a day, and you can message a real coach anytime. One plan covers running, strength, HIIT and mobility, so your marathon build sits alongside the general strength and mobility work that keeps your legs healthy over a long block. The plan flexes around your life, and if your week gets busy you can use Flexi Swap to move sessions or ask Edge AI to adjust things.

It tracks your progress and syncs with Apple Watch, Garmin and Coros, so your runs and long runs stay in one place. Whatever your starting point, the plan is shaped around the number of weeks you actually have before 25 April. There is a free 7-day trial, then from £19.99/month. Edge builds general strength and mobility into every plan. Any marathon-specific extras you want to add, or any niggle you need looked at, are best worked through with a qualified professional. Joined by 18,000+ members, Edge is about making fitness feel good for everyone.