How to Train for the London Marathon: A UK Runner's Guide
Whether you've secured a ballot place, a charity place, or a Good for Age entry into the TCS London Marathon, the training principles behind a successful marathon block are the same — what changes is how well you structure the months in between now and race day. London's flat, largely closed-road course and famously huge crowd support make it a genuinely fast, well-supported place to run a marathon, but none of that substitutes for a properly structured build-up.
Base building comes first
Before any marathon-specific speed work, most training plans spend several weeks simply building a consistent, comfortable weekly mileage base. Skipping this stage to get straight to "marathon pace" sessions is one of the most common reasons runners pick up injuries mid-block. A realistic base-building phase means running frequently enough, at an easy enough effort, that your body adapts to the habit of regular mileage before intensity gets layered on top.
The long run is the centrepiece — but not the only thing
A weekly long run building gradually toward 18–22 miles gets most of the attention, but the sessions around it — easy running, some marathon-pace segments, and genuine recovery days — are what let you absorb that long run without breaking down. A common mistake is treating every run at a similar effort level; the sessions either side of your long run should be noticeably easier, not just shorter.
Don't neglect marathon-pace practice
Beyond simply covering distance, dedicated marathon-pace segments within training runs — even just a few miles at goal pace within a longer, easier run — help your body and mind get genuinely familiar with what race pace feels like under fatigue, rather than discovering it for the first time on the day itself.
Tapering is training too
The two to three weeks before race day matter as much as the eighteen weeks before them. Reducing volume while maintaining some intensity lets your body arrive at the start line recovered, not just rested — the taper is where fitness gained over months gets consolidated, and cutting it short or panicking with extra late training is a common way to arrive under-recovered on race morning.
Matching your supplement routine to the block
A marathon block asks a lot of four things at once: daily energy and immune resilience across months of training, joint durability under repeated impact, pre-run and race-day performance, and overnight recovery so each week's training is actually absorbed. RunnerVits built the Marathon Race Ready Bundle around exactly those four pillars, so the supplement side of training doesn't need to be assembled piecemeal from separate, unrelated brands.
Quick answers
How many weeks should a London Marathon training block be?
Most plans run 16–18 weeks, allowing enough time for a genuine base-building phase before marathon-specific work begins, followed by a proper taper.
What if I've never run further than a half marathon before?
A longer build-up (18+ weeks) with a gradual, patient mileage increase reduces injury risk significantly compared to compressing the same distance progression into a shorter timeframe.