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How to run a gluten-free marathon

Wait! There are gluten-free marathons?

Ali Walsh running
Coo, those trainers are white!

Not quite what I meant (although obviously it'd be fab if they did exist).

I'm talking about running a marathon gluten-free. That means:

(a) learning to fuel your body with a healthy variety of gluten-free food;

(b) not having the same gels or energy bars as the masses; and

(c) not being able to accept sweets off kind folk in the crowd.

So how do you do it?

First of all, find a pair of shorts with a pocket. And not the floaty shorts with an elastic waistband. Instead, a pair of cycling shorts (as they've traditionally been called) with at least one deep pocket. I went to Sweaty Betty for mine and accidentally discovered I got 20% off because I was running the London marathon (you just need to give them your race number).

Sweaty Betty shorts
These are the shorts I chose (with the all-important pocket!)

Why not the floaty shorts? For me, it's because I don't want what's in my pocket jiggling up and down (or worse, falling out). That, plus the elastic waistband tends to leave a funny serrated look to my waist which gets itchy. So I go for the smooth lycra instead, which is especially useful if you're wearing a costume (and yes, I dressed as a banana for my marathon). I'll get to what you'll be putting into the shorts later.

The 2 food issues you'll need to focus on

First up is the need to fuel your body for runs without worrying about gluten. When I did my marathon this year, this meant focusing on a range of gluten-free carbohydrates that weren't just white rice and jacket potatoes (much as I like them). You'll know from my 7 Day Swap how important this is (if you've not yet checked it out, head over and grab your program here).

That means finding carbs that taste delicious and aren't boring. My favourites include:

  • Quinoa (yes, quinoa! You just have to learn to cook it properly - i.e. no more than 8 mins and preferably choose red quinoa because it's tastier, I reckon);

  • Brown rice (basmati, for a nuttier flavour);

  • Sweet potatoes (especially when made into wedges);

  • Buckwheat flakes (fab as an alternative to overnight oats); and

  • Mash (I mean, what could be better comfort food on a cold winter's day?)

Next, I wanted to make sure I was getting enough fuel for my body but not feeling too sluggish for my run. If you want to do the same, you may need a little trial and error but here's my starting point if it helps.

I began my training at approximately 9 stone 9lbs (61kg) and decided I needed to be in a bit of a deficit so I could get rid of my gut (I really didn't enjoy the sensation of running with a belly).

But I didn't want to deprive my body or feel I was on a horribly mean diet. So I opted for 1,900 calories a day (no matter what my day entailed) and knew (from doing this before under the advice of an expert PT) I'd be likely to take 3 months or so to see a difference in my body. I used my Fitbit to track my calories and decided to have treats every day (like icecream or chocolate) but in small portions (w-a-a-y smaller than I'd have dished up without weighing them) so I'd get enough protein, fibre & healthy carbs from other foods to feel full.

Now this approach won't necessarily work for everyone as we all have different needs depending on what our bodies are used to, our previous exercise history, our height, weight and so on.

But I always think it's encouraging to know exactly what someone else did to have a rough idea of how it might be done for you (and obviously check with a medical practitioner before embarking on any changes).

And you can see from my pics that it worked! My weight at the end was approximately 9 stone (57kg) and not once during the time on the calorie deficit did I feel deprived, which I think is really important. I mean, what's the point in slogging your guts out and feeling incredibly hungry all the time? That doesn't sound like fun and I wanted my marathon training to be enjoyable.

What does a daily diet look like?

I like variety so in the chart below there are 3 examples of the types of food I go for. On weekdays I make a very quick 'carrot cake' for breakfast in my air fryer (delish!). If you want to do something similar, just take a baked oats recipe and replace the oats with buckwheat flakes. (I can't eat oats, including gluten-free oats, because I react to avenin.) I get my buckwheat flakes from Healthy Supplies online because they don't have any 'may contain gluten' fears.

For 2 dinners a week my family and I enjoy a Mindful Chef meal. They're all gluten-free so I can have anything and it brings real variety into my life. The last few I've had have included Braised Chicken Thighs & Rainbow Rice, Mexican Pork Chilli, Hot Smoked Trout with Potato Salad and Springtime Creamy Chicken Gnocchi. And I promise these are as delicious as they sound! All you do is order the number of meals you want per week and they deliver. It's wonderful!

Mindful Chef gluten-free meal made by Ali Walsh
Mindful Chef steak & egg with sweet potato fries

Friday is a more casual day (i.e. I often get a takeaway curry) because I'm often wiped out by the idea of cooking at the end of the week. I really trust my local curry house and have had countless delicious curries from them. Sometimes I'll do brown rice to go with the curry, rather than get their boiled white rice, which means I've had more fibre (and saved a few £££).

I've more time on a Sunday to make things fun (like pancakes from a gluten-free flour blend) and obviously since I'm a Brit I enjoy a Sunday roast, most of which is naturally gluten-free. I buy freefrom gravy granules (I know, I know, such a cheat) and condiments like cranberry sauce if we have turkey or wholegrain mustard if we're having beef (some mustards have gluten in but the wholegrain one from Lidl is my current go-to; I always check the ingredients & allergens just in case, though).

As for alcohol, I practically stopped drinking because if I had a large glass of wine, I'd feel hungry the next day, and I realised that could have been replaced with a jacket spud. That said, I did eat chocolate most days so there were times where I favoured a small glass of wine or a shot of whisky over a piece of dark chocolate. (Yes, I did mention whisky - my favourite!)






Buckwheat "carrot cake" & chia seed pudding

GF tortilla wraps with fresh spinach, ham, egg whites & a GF protein bar

Mindful Chef meal & a Coconut Collaborative choc pot


Purition with protein yogurt & GF granola

GF quiche with ham, broccoli & protein cookie dough bites

Takeaway chicken curry & rice + a small glass of wine


GF pancakes with protein yogurt & sliced apple

Roast chicken, boiled new potatoes & vegetables

GF pasta with tuna, veg & cheese + a Peppa Pig icecream lolly

You may notice I don't snack. It seems my body prefers to have plenty of time between meals (apparently it can be better for our gut health). Adopting this approach seems to stave off my IBS, which is a real bonus, and the reason I can do it is because I don't feel hungry.

Wot? No hunger? Really?

Yup. And it's all thanks to reading about glucose levels in Jessie Inchauspe's The Glucose Revolution. She goes into the science behind learning how to eat (rather than what to eat) and I learnt hacks to make my life so much easier. I really recommend reading the book but (to save you time) I pretty much added a spoonful of white wine vinegar before my meals or a plethora of broccoli (tenderstem when I was feeling flush).

Fibre (and why gluten-free diets need to focus on it)

It's not that people on a gluten-free diet necessarily need more fibre, it's just that it's easy not to get enough because you're not having things like Weetabix for breakfast any more. (Add those types of cereal along with wholewheat sandwiches at lunch and it means 'normal' people may find it easier to access a fibre-filled diet.)

Apparently we should aim for 30g a day but that'll depend on what your body needs. If you have IBS, it may be you can't tolerate fibre as well as others, but check with a registered nutritionist to find out what works for you. For me, I add psyllium husk and chia seeds into my daily diet and foods like Purition or brown rice help, too.


If you're into running already then you probably know a bit about focusing on macronutrients (or macros) - i.e. fat, carbohydrates & protein. But it's important not to forget the micronutrients, too, so be careful to look at things like vitamins and minerals to be sure you can run safely. You might think your aching legs are the result of running or not doing enough of a warm-up but don't overlook your diet for the cause. The best way to figure it all out is to use an app and log all your food (which is precisely what my Fitbit does when I track what I'm eating). You can use the free version of MyFitnessPal if you don't have a Fitbit (or Apple watch) but be mindful it won't always log the exact micronutrients of the food you're having. Therefore, don't panic if one day it looks as though you've had no vitamin C. Look at what you've eaten. II you've had a kiwi and it's not registered the vitamins then find out the exact amount you've had from your food and adjust the settings in your tracker accordingly.

Calcium & Vitamin D

It's clear running can put stress on our joints so to ensure good bone health & muscle function, we need to look at our calcium intake.

If you have coeliac disease (like me) then you may know you're meant to have more calcium than most. While it's important to get it from food if you can (e.g. yogurt, broccoli, tuna etc...) I was told by my coeliac GP to up my calcium intake with Osteocare tablets (the ones you can get in the supermarket - just check underneath that the ingredients suit you). So I now have 2 a day. They also contain vitamin D which aids the absorption of calcium (and is hard to get except from the sun, which was in short supply on my winter runs, I can tell you).

How to fuel on the run itself (and avoid 'The Wall')

I decided I couldn't eat during a run. I know people say bananas are good (and obviously gluten-free) but I didn't think I'd get on well with them. For a start, the taste of a banana repeating on me didn't appeal. And second, who wants to put a banana in their pocket?

But I knew I had to have something because I wanted to avoid hitting 'the wall', which happened to me on the first marathon I ran. It's definitely not something to repeat. (I felt as though someone had cut out my stomach and told me to carry on. Hideous.)

I also knew I'd have to train with the fuel I chose so there were no surprises on the day (erm, toilet surprises if you're wondering - and there's nothing like funny bowels to set a coeliac off). But what could the fuel alternative be?

Energy gels

The very idea of energy gels makes my stomach nervous. Exactly how many unpronounceable ingredients are in them? And are they safe? Surely it's far better to concentrate on stuff your body knows? And that's when I came across Protein Rebel. They produce a version of energy gels but it's only maple syrup and salt - i.e. things my body already knows from consuming them fairly regularly.

So I tried a few big runs with them but realised I'd need quite a lot to get me through a marathon. And surely I could make my own...

I got a screw-cap protein yogurt and, after eating it, washed it out thoroughly. I mixed together some sea salt and maple syrup and poured it into the yogurt sachet using a tiny funnel (you can get them from Poundland in reusable bathroom container sets).

This went securely into the pocket of my Sweaty Betty shorts (told you I'd come back to those) and proved invaluable as I ran round because a quick swig of the maple syrup meant I had an instant energy source without the faff of a plastic energy gel pack to rip open (or dispose of).

Eating the day before the race

Tempting as it might be to go out for a meal the night before, the last thing I wanted to do was accidentally get glutened. So I made my own meal (chicken sosaties, brown rice & broccoli) and had a slightly bigger portion than usual. I also enjoyed a glass of white wine, which I was pleased about because it felt like a mini-celebration (oh, the excitement for the run!).

Race day

Because I was staying at someone else's house, I didn't want to have something for breakfast I'd not eaten before (fear of gluten or otherwise, as I was sure my tummy would want food it was used to) so I made my buckwheat carrot cake and brought it with me). I had a slightly larger portion than usual (but not by much as I didn't want to feel overloaded).

The London Marathon 2023
Spot the banana!

The event itself

Sure enough, lots of the crowd were offering sweets. There were bananas, too, but I swerved those (even though I was dressed as one) for the reasons I mentioned before. And so the maple syrup came into its own: I took a swig from about 6 miles onwards every 3 or 4 miles and, miracle of miracles, I avoided The Wall! I was so pleased it had worked, even if my clumsy fingers didn't quite replace the cap properly & I ended up with maple syrup crusted shorts!

Ali Walsh running the London Marathon as a banana
Here I am battling the wind & rain in my banana costume

The finish-line goody bag

You can probably guess what was in it: food I couldn't have (this time, a massive flapjack). But I had the team from Coeliac UK on hand with gluten-free snacks so I was able to tuck into a packet of crisps and an Eat Natural bar, which was wonderful.

The celebratory meal

Often when a marathon's over it's a case of 'eat where you can find a table'. I hadn't booked anything because I wasn't sure what time I'd finish and how long it'd take for my family to find me afterwards, so we all ended up at a steakhouse, which is a pretty safe bet for a coeliac. I avoided the chips as they had a shared fryer, but a steak with broccoli followed by icecream was the perfect end to a wonderful day. Honestly, running a marathon was one of the best days of my life, and I hope it'll be yours, too. Here's the video from the London Marathon I did for inspiration!

Read more about the start of my marathon training here.


Hi! Great to have you here...

My name's Ali and I help people on gluten-free diets have a better, easier and healthier lifestyle. 

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