Published: 20/04/2026 | By: Ally head
Race week is here – and so are the nerves. If your taper has you second-guessing everything from carb loading to whether you’re actually ready, this is the guide you’ll wish you had sooner. Written by a 10x marathoner, it cuts through the noise with real, practical advice on fuelling, hydration, mindset, and avoiding race-day mistakes. Consider this your ultimate race day bible – everything you need to feel calm, confident, and ready to run your best 26.2.
It’s finally here. London Marathon month! Race week! Taper time! And for the 50,000 of you gearing up to complete the 26.2-mile distance come Sunday, this week will be a journey. From the bubbling in the pit of your stomach to the tricks that the taper starts playing on your mind, making it through the last week of your training block can be just as much of a challenge as the 14+ weeks of hard work that have come before.
You won’t be alone if you find that not running as much as you’re used to is a bit of a shock to the system. There’s even a word for it – “maranoia”, otherwise known as “the often irrational worries you face in the final days before running a marathon,” according to The Running Channel. Often exacerbated by the fact that you suddenly have so much free time, if you’re anything like me, your brain will fill that free time with running-related questions.
I remember the week before my first marathon so well. The nerves, the excitement, and, as above – the 11 pm Google searches as 101 questions rattled around my brain. Maranoia hit – and it hit hard. How much water should I drink in the week before a marathon? What actually is a carb load? How do I know if I'm ready?
The simple answer is, you’ll never know when you’re ready. All you can know is that you’ve done the hard work now – if it’s the week before race day, it’s time to trust in your training, work on nurturing a positive mindset, and rest, rest, rest. That said, I wish I’d had a bible that I could have referred to prior to my first 26.2 – a complete run down of every question I’d been unable to find straight answers for. Which is where the idea for this article came from.
For those of you who don’t know me, I’m Ally , a Senior Health Editor and 10x marathon runner. I’ve run the London Marathon three times, running a sub-four-hour time on the course in 2019 and a Boston Qualifying time on the same route two years later, so I know a thing or two about how to prepare both your mind and body for your first 26.2. Keen to read my tips? Keep scrolling.
What should I prioritise in the week leading up to my marathon?
According to every single expert I’ve spoken to, it’s really quite simple: in the week before your marathon, you should be focusing on rest, recovery, and an adequate taper. Not sure what a “taper” actually is? It’s essentially just a reduction of mileage so that your legs feel fresh come race day.
Remember, less is more this week – sleep is your best friend, and has been scientifically proven to be one of the easiest ways you can boost your performance come race day. I’m also a big fan of using this time to visualise the finish line, journal about my training block, and to start to run through my race day mantras in my head. This isn’t for everyone, but again, it has been research-backed to be beneficial when times get trickier, and you feel more fatigued towards the end of the race.
If you’re not quite sure what that looks like day to day, I’ve written a handy checklist for you, below.
What should I eat before a marathon?
There’s one simple and universal answer to this one: whatever you’ve eaten in training.
As per most nutritionists' guidelines, I like to steadily start increasing my carb intake around 2 to 3 days out from the race. Any earlier, and you risk feeling lethargic and fatigued; any later, and you might not be adequately fuelled come race day. This normally looks like including a few more carb-based snacks, and centring my meals solely around carbohydrates, rather than eating way more than I’m used to. Carb drinks, like Lucozade, orange juice, and pre-made branded mixes, can also come in handy.
The night before, I always have pasta; morning of, I’ll have a bagel with peanut butter, honey and a banana, with a small pre-race snack (another banana, a Lucozade, and a gel) an hour or so before the race starts. But personal preference is really key here, and following someone else’s pre-race nutrition plan isn’t necessarily the answer. Trust yourself – you’ll know what worked for your long runs and what you digest best.
The key here is doing what you’ve done in training and what works for your body – what works for your one won’t necessarily work as effectively for the next.
How many gels should I take?
Again, this one’s personal and something you likely found out the answer to during your long runs. As a general rule of thumb, most sports nutritionists and dieticians will recommend taking a gel every 25 to 45 minutes, hitting 30-90g of carbohydrate each hour (FYI, a gel contains anything from 20 to 40g of carb per packet).
Ensure you start fuelling early on so as to avoid hitting the dreaded wall later on in the race.
More experienced runners can aim for as much as 120g of carbohydrate an hour, but it’s essential to have practised this in training to avoid stomach issues on the day.
If all of the maths is a bit much for you – aim for a gel every 30 minutes, and take as many gels as you may need, deduced from your predicted finish time and with a few spares. For example, if you’re aiming for:
One of my favourite brands is Science in Sport.
Should I drink at every water station?
This leads me on to the next question nicely – hydration. In the days leading up to the race and as we’ve touched on, make sure you’re drinking plenty of water, avoiding alcohol where possible and adding electrolytes to top up your sodium, potassium, and magnesium stores if you’ve practised with them in training.
Come race day, most qualified experts advise drinking a glass of water first thing, but then avoiding water if possible for the hour before the race. This tactic is simple – to ensure you don’t end up desperately needing a wee come mile 13 – but you know your body best, and if you’re thirsty or feel like more water intake will be beneficial for your race, trust your gut.
During the race, it’s not essential to drink water at every single station, but it is advised to sip water as and when possible, and to make use of the aid stations, especially if there aren’t loads along the course. You’ll be able to research where the water stations are in advance on the course map, which I’d recommend, so you go into the race armed with the relevant information. Similarly, how much water you’ll need will vary depending on race day weather conditions and how much water you drank during training, so be prepared to play it by ear.
Top tip: if the water being handed out is in cups, try to squash the cup into a flatter “V” or spout shape so you can more neatly pour the water into your mouth and prevent it from spilling all over you (although, that will happen at points – so don’t be too surprised!).
If it ends up being a particularly hot day, some experts also recommend pouring any water you don’t drink over your head to keep you cool and reduce your risk of overheating.
How to avoid "hitting the wall"?
You’ll all have heard of the dreaded wall, which Simon Pegg’s character Dennis infamously hit – and overcame! – in Run Fat Boy Run. In short, it’s a state of severe physical and mental exhaustion that many runners hit around miles 18 to 22. It can manifest as tired, heavy legs, mental exhaustion, and an overwhelming urge to stop running.
But fun fact for you: “the wall” tends to be caused by depletion of glycogen stores in your liver and muscles. In short, it’s your body not having enough carbohydrates to continue functioning. One sure-fire way to avoid this is to stick to your fuelling plan – if you’re topping your glycogen stores up consistently, you run a far lower risk of running out.
There’s a mental aspect too, of course – a marathon is an unforgiving distance, so make sure you have your race day mantras on hand to push yourself through when your body is fatigued.
How to prevent chafing?
I’m well versed in this area, as a sweatier-than-normal runner who’s handled many chafed thighs, knees, and armpits in her time. I now have a pretty fail-safe strategy to prevent chafe, and seriously advise doing them even if you haven’t ever chafed before or don’t think it’ll be an issue for you come race day.
First and most importantly, don’t wear new kit on race day. If you haven’t sweat-tested new kit, it’ll be stiffer, plus may have hidden friction points (a hidden seam, niggly under-arm cut) that could lead to severe – sometimes even race-ruining – chafe.
Secondly – BodyGlide, BodyGlide, BodyGlide. The balm is a godsend, working as a protective, invisible, non-greasy barrier on the top of your skin. I apply a generous layer to my feet, knees, thighs, torso, and armpits while I’m getting ready, and often take some with me to the start line so I can reapply. My advice? Pay particular attention to under your arms, between your legs, and around your nipples, for men, and consider plasters if this is a problem area for you.
If you are someone who struggles with chafing, it also wouldn’t go amiss to take a small pocket-sized BodyGlide or tin of Vaseline for race day – I get my cheer squad to have some on hand in case I need some as I run past them. Most major marathons will also have paramedics at the side of the course with Vaseline on hand, ready for you to apply.
How to deal with pre-race nerves?
Google is awash with tips for minimising race day nerves, but I’ve often found reading up a little overwhelming as there are so many ways to tackle it.
In my experience, the following works a treat for rocking up to race day feeling calm and collected:
Is it okay to walk during a marathon?
Short answer: Without a doubt, and if anyone tells you otherwise, they’re wrong. Sometimes a walk can be a useful physical and mental reset, and certainly nothing to be looked down on. Every runner is different!
I walked during my Valencia Marathon in December due to a stitch issue and still managed a Boston Qualifying time of 3 hours 13 minutes.
What if I can't finish?
The likelihood is, you’ll absolutely smash race day – you’ve done the training now, “callousing your body to the distance,” as elite marathon runner Anya Culling once said. Trust that this is your victory lap – all that’s left to do is enjoy the thing.
Not finishing isn’t a reflection on you, the months of training, or your abilities. It just might not have been your day – and that’s okay.
In official terms, most marathons will then list your entry as a DNF (Did Not Finish). Some races may still give you a medal, but it’s course-dependent. Remember, not finishing doesn’t make you a failure – It makes you brave for daring to try.
How do I know I’m ready?
The age-old question. The honest answer to this question is, we never know – but the beauty of being a runner is that we give it our best shot anyway, trusting in our training and motivated by more than miles on a watch or a medal at a finish line.
If you’ve trained consistently and to the best of your ability for the last few months, your body will be ready. And the early starts, miles when you really can’t be bothered, and long weekend runs hitting mileage you used to dream of will have prepared you mentally, too.
Half the battle is always mental – whatever your reason to run or cause close to home, hope will carry you to that finish line. Because running’s never just about the running. It’s always been about much, much more.
All images featured are taken from @allyyhead 's Instagram