HOW TO PACE THE LONDON MARATHON – A GUIDE

Published: 13/04/2026 | By: Emma Kirk-Odunubi

Most runners don’t miss sub-4 at the London Marathon because they’re unfit – they miss it because they pace it wrong. After 15 marathons and 12 failed attempts, running ambassador Emma Kirk-Odunubi finally cracked the code with a 3:58. This is the exact pacing and fuelling strategy she used – broken down mile by mile – so you don’t make the same mistakes she did.

I have run the London Marathon four times, and last year I crossed the finish line in 3:58 – finally breaking four hours for the second time. This is everything I wish I had known before my first London, and how to pace your way to that elusive sub-4.

London is a mostly flat course, but do not let that fool you. The energy of the crowds, the flow of the course, and a few psychologically brutal miles make it a race that will absolutely punish you if you go in without a plan.

On paper, the course looks simple. In reality, it is a masterclass in emotional self-control and fuelling strategy.

The number one mistake runners make at the London Marathon is going out too fast.

The number two mistake? Going out too fast.

SECTION BY SECTION: LONDON MARATHON PACING IN PRACTICE

The First 10K: Be Boring. Please.

The opening miles feel wonderful. You are fresh, the crowd is screaming, and everyone around you looks like they are flying. There is also a gradual early downhill that tricks your legs into thinking you are running effortlessly. You are not – you are burning through energy you will desperately need later.

Run the first 5K at a pace that feels almost embarrassingly slow. Stay with the pack, avoid weaving through gaps, and let the congestion keep you honest. If people are overtaking you and you feel like you are jogging, you are doing it right.

Tower Bridge to Halfway: The Danger Zone

This is where it gets emotional – and where most sub-4 attempts quietly fall apart.

Tower Bridge is one of the greatest experiences in sport. The noise is unbelievable. Your pace will surge if you let it. I know, because it has happened to me more times than I care to admit.

Enjoy it. Take it in. Then calmly bring your pace back under control. It happens to me every year – yes, even though I know not to push – but the feeling is unmatched.

Aim to hit halfway in around 1:58 to 2:00. Crossing halfway in 1:54 feeling great is not a bonus – it could be a warning.

Canary Wharf and the Isle of Dogs: Miles 13 to 19.5

Real talk: this section is hard.

The course twists through residential streets, the crowd thins out, and the tall buildings in Canary Wharf will mess with your GPS watch. Do not panic if your pace readings jump around – trust your effort level over your watch.

This is where I bring out my biggest playlist bangers. Have something ready that fires you up – these miles require something to hold onto.

GPS can be unreliable through Canary Wharf – run by feel and trust your training. Watch for tight congestion just before Cutty Sark – be patient and do not waste energy weaving. Keep fuelling on a timer, not based on how you feel.

Miles 19.5 to the Finish: Time to Race

If you have paced and fuelled correctly, this is where your race truly begins.

The crowds build, the landmarks come thick and fast, and you have permission to start pushing. Aim to run the final 10K progressively faster if your legs allow it. A negative split marathon is earned in the first half by holding back.

At around mile 23, take your headphones out. What happens in the final three miles of London is something no playlist can match. The roar of the crowd past the Tower of London, then downhill towards Embankment, Big Ben, and onto The Mall is unlike anything else in running.

Last year, I cried during that final 5K. Properly cried. Let it happen – and be proud of what you are achieving.

The last three miles are London doing what London does best. Headphones out. Run with your heart and let the crowd carry you home.

FUELLING IS KING

Forget fuelling at mile markers. Fuel every 25 to 30 minutes on a timer from the very start of the race. Set an alarm on your watch and take your nutrition when it goes off, regardless of how you feel. By the time you feel like you need a gel, it is already too late.

In my early marathons, I took on far too little fuel because I did not understand how important it was. Once I started consistently hitting 60–90g of carbohydrates per hour, my results improved dramatically. Pair every gel with water, carry nutrition you have practised with in training, and do not try anything new on race day. Get your fuelling right and your pacing will follow. Get it wrong, and no amount of training will save you after 20 miles.

LASTLY…

Whether this is your first marathon or your fifteenth, the London Marathon is a privilege. Pace conservatively in the first half, fuel consistently throughout, and trust the process when it gets tough through Canary Wharf.

Last year, I ran 3:58 after 12 previous failed attempts at sub-4. The plan held. I trusted my training. The fuelling worked. And my legs held on just long enough. Yours will too.

Your sub-4 is absolutely within reach. Most importantly, HAVE FUN!

I will see you on the start line as I chase it again this year.