London Marathon Prep with Jenn Humphries: Race Day Tips

So, you’ve signed up for the London Marathon…now what?

Maybe you’re buzzing with excitement, maybe you’re wondering what on earth you’ve gotten yourself into—or maybe it’s a little bit of both. From long runs to fuelling strategies, race-day nerves to post-run recovery, there’s a lot to think about.

That’s where Jenn Humphries comes in. She’s tackled the highs and lows of marathon training and knows exactly what it takes to make it to the start line feeling strong (and actually enjoy race day!). In this guide, she’s sharing her best tips—from training smart to smashing race day—so you can take on the London Marathon like a pro. Let’s get into it!

Jenn Humphries (@runcoachedbyjenn) isn’t just a running coach—she’s a runner who gets it. 

With a passion for trail running and a love for endurance challenges, Jenn has tackled everything from marathons to ultra-distance events like WhyWeRun. Now preparing for her third London Marathon, she’s officially a veteran of the iconic race.

But Jenn’s impact goes far beyond her own achievements. Through her social media, she shares honest, no-nonsense advice to help runners cut through the overwhelming amount of information out there. She knows firsthand that running isn’t always smooth sailing—some days you feel unstoppable, and others, well… not so much. 

That’s exactly why she became a coach: to guide people through those moments, to help them reach their potential, and to remind them that running is about more than just numbers. As both a coach and London Marathon vet, who better to hand out advice to everyone taking on the challenge for the first time this year...

When it comes to marathon training, Jenn's all about building the foundation first. Strength training is a non-negotiable in her book—not just to prevent injuries, but to actually make you a better runner. A solid strength routine, especially during a training block, can be the difference between hitting race day ready or barely making it there at all (check out her Instagram for workout ideas).

Then there’s nutrition—a lesson Jenn learned the hard way. Looking back at her first London Marathon, she admitted it’s no surprise she nearly collapsed at the finish line. Since then, she’s put a huge focus on fuelling properly, both in training and leading up to race day, and the results speak for themselves. 

“You may feel like a walking carb by the end of the training block, but it’s worth it,” she told us. Her golden rule? Never try anything new on race day. That means resisting the urge to grab whatever gel is being handed out mid-race—stick with what you know works for your body.

And of course, there’s the running itself. While she swears by interval training for her own progress, Jenn believes that easy runs are where most runners—especially beginners—see the biggest improvements. 

“The easy run builds your engine and endurance, which is ultimately what you need to cover 42k". Long runs and easy efforts lay the groundwork, and only once that base is solid should runners start adding in speed work. Above all, Jenn emphasises listening to your body. Marathon training isn’t about racing every session—it’s about building strength, endurance, and confidence so you’re ready when it really counts.

Marathon training can feel lonely. The long hours on the road, missing social events, and constantly prioritising training can make it easy to feel like you’re on your own. Jenn completely gets that. As both a marathon and ultra runner, she’s had to make sacrifices, but she’s found that being open and honest with her friends about how much her races mean to her helps massively.

Then there’s the mental battle on solo runs. It’s easy for negative thoughts to creep in. Jenn’s advice? Talk to yourself like you would a friend. If you wouldn’t tear them down, don’t do it to yourself. “Life makes you better at running, and running makes you better at life.” That mindset shift can be a game-changer.

Even your race day outfit impacts your confidence. Jenn swears by “look good, feel good,” but with one rule—test everything first. That new kit might boost confidence, but you don’t want surprises like chafing or discomfort over 26.2 miles.

Most importantly, don’t let your goals take the joy out of the experience. Training for a marathon is a massive achievement in itself, and it’s easy to get caught up in expectations. Make sure you enjoy the ride.

Race day is finally here, but before you even step onto the course, there are a few things to keep in mind. 

First up—getting to the start line. London Marathon logistics mean you could be waiting around for a while, so Jenn’s top tip? Bring a snack. Your breakfast might have been hours ago, and you don’t want to start running on empty. And while you’re waiting, stay warm! A throwaway jumper is a lifesaver—it keeps you comfortable before the race, and the best part? It gets donated to charity.

Once the race starts, it’s easy to get caught up in the moment. You’ll be surrounded by thousands of runners, all looking fresh in their new gear, and doubt can creep in. Remember to focus on your own race. Trust your training and stick to your plan. You’ve put in the work, and you’re more than ready for this.

There's one final thing that we haven't yet mentioned. TAPE.

Jenn used tape for both her 2023 and 2024 London Marathons—not just for injury prevention but as a mental boost, like warpaint for race day. She’s also relied on it during ultras to prevent blisters and chafing, proving that tape isn’t just for injuries.

A massive good luck to everyone gearing up for the London Marathon! A huge shoutout to Jenn for all her brilliant advice—hopefully, it helps make race day that little bit smoother. And if you need some taping tips to keep you moving, head over to our learn page for easy step-by-step guides.