How to Train for the London Marathon: A Complete Guide From a Coach
Getting a place in the London Marathon, whether through the ballot, a charity spot, or a good-for-age time, is genuinely exciting — and then the reality sets in. Twenty-six-point-two miles through the streets of London is a serious undertaking, and how you train over the coming months will decide whether race day feels like the best day of your running life or a painful struggle from mile sixteen onwards.
As a coach, I've guided runners through London Marathon training at every level, from complete first-timers to people chasing sub-three-hour times. This guide walks through exactly how to train for the London Marathon properly, covering your training plan, weekly mileage, long runs, pacing, nutrition, and the taper, so you arrive at the start line in Greenwich ready, not just hopeful.
How Long Should Your London Marathon Training Plan Be?
Most marathon training plans run for somewhere between sixteen and twenty weeks, depending on your starting fitness. If you're already running regularly and comfortably covering five to ten kilometres a few times a week, sixteen weeks is usually enough. If you're newer to running or coming back after a break, closer to twenty weeks gives your body time to adapt gradually, which matters far more for a marathon than it does for shorter distances.
Trying to compress marathon training into a shorter window is one of the most common mistakes I see. The marathon is far less forgiving of rushed preparation than a 10k or half marathon, because so much of what gets you round the full distance comes from cumulative weeks of training, not fitness you can build quickly in the final month.
Building Your Weekly Mileage Safely
Weekly mileage should build gradually rather than jumping around from week to week. A common and sensible approach is increasing your total weekly distance by no more than about ten percent from one week to the next, with an easier, lower-mileage week roughly every third or fourth week to let your body absorb the training rather than simply piling up fatigue.
Beginner marathon training plans often peak somewhere between thirty and forty miles a week, while more experienced runners chasing a faster time might peak considerably higher. What matters far more than hitting a specific number, though, is consistency. Four manageable, sustainable runs a week for months on end will get you to the start line in far better shape than an ambitious plan you can only half stick to.
The Long Run: The Heart of Marathon Training
If there's one session that defines marathon training, it's the weekly long run. This is where you build the endurance, and just as importantly the mental resilience, needed to keep moving for over four hours on race day. Most marathon training plans build the long run up gradually to somewhere between eighteen and twenty-two miles in the weeks before the taper, run at a genuinely easy, conversational pace rather than anything close to race effort.
The long run also doubles as your chance to practise everything you'll need on race day itself: the shoes you'll wear, the nutrition you'll take on board, and the pacing strategy you plan to run. Race day is not the moment to try anything new, and the long run is where those habits get built and tested safely.
Marathon Pacing Strategy for London
The London Marathon course is famously flat and fast, which makes it a brilliant course for a good time, but it also makes it dangerously easy to go off too quickly in the excitement of the crowds and the early miles through Greenwich and Woolwich. A sensible pacing strategy is running the first half slightly conservatively, ideally even a touch slower than your target pace, and aiming to run the second half at least as fast as the first, if not faster.
Working out your goal pace properly, based on your actual training and recent race times rather than what you'd simply like to run, is one of the most valuable things a coach can help with. Going out too fast is by far the most common reason marathon runners fade badly in the final six miles, particularly through the tougher stretch around Canary Wharf and the long straight along the Embankment toward the finish.
Marathon Nutrition: Fuelling Your Training and Race Day
Nutrition becomes genuinely important once your long runs start pushing past ninety minutes, because your body's stored carbohydrate simply isn't enough to fuel a full marathon effort on its own. Most runners benefit from practising taking on carbohydrate, whether through gels, chews, or sports drinks, during long training runs well before race day, so your stomach is used to it and you know exactly what works for you.
In the final few days before the marathon, many runners increase their carbohydrate intake slightly to top up their energy stores, commonly known as carb-loading, though this matters far less than getting your fuelling right during the race itself. On the morning of the London Marathon, a familiar, carbohydrate-based breakfast eaten with enough time to digest before the start is far better than experimenting with something new.
Injury Prevention During Marathon Training
Marathon training puts a lot of repeated strain on the body, and niggles are common if you increase mileage too quickly or ignore early warning signs. Building in easy weeks, prioritising sleep and recovery, and addressing small issues like tight calves or a sore knee early, rather than running through them, will keep you training consistently rather than losing weeks to injury.
Strength training, even just twice a week, is one of the most underused tools in marathon preparation. Stronger glutes, hips, and core help you maintain good running form as fatigue sets in during the later miles, which is exactly when injuries and form breakdown tend to happen.
The Taper: Why Doing Less Before Race Day Matters
In the final two to three weeks before the London Marathon, your training volume should reduce noticeably, even though this often feels uncomfortable after months of building mileage. The taper allows your body to fully recover from months of training and arrive at the start line fresh rather than fatigued. Cutting mileage doesn't mean losing fitness; the fitness is already banked from the months of training behind you, and the taper is simply what lets you access it fully on race day.
London Marathon Race Day Tips
On the day itself, stick to the plan you've practised in training rather than getting swept up in the atmosphere. The crowds along the London Marathon route are genuinely incredible, particularly through Tower Bridge around the halfway point, and it's easy to run faster than intended purely on adrenaline. Trust your training pace, take on fuel early and consistently rather than waiting until you feel like you need it, and remember that the last six miles of a marathon are as much about mental resilience as physical fitness.
Frequently Asked Questions About Training for the London Marathon
How many months does it take to train for the London Marathon? Most training plans run for sixteen to twenty weeks, so roughly four to five months, depending on your starting fitness level.
How many miles a week should I run when training for a marathon? Beginner marathon training plans typically peak between thirty and forty miles a week, while more experienced runners often train at higher weekly mileage. Consistency matters more than hitting a specific number.
What is a good beginner pace for the London Marathon? There's no single "good" pace — it depends on your training and current fitness. A coach or a recent race result is a far more reliable guide than comparing yourself to other runners' times.
Do I need to run the full 26.2 miles in training? No. Most training plans peak at around eighteen to twenty-two miles for the longest run, since the taper and race day adrenaline typically carry runners through the final few miles.
What should I eat the morning of the London Marathon? A familiar, carbohydrate-based breakfast that you've already tested during training, eaten early enough to digest before the start.
