Swim Serpentine, the 2 mile swim in London’s Serpentine lake is on a lot of runner’s bucket lists for one reason… the London Classics.

The London Classics comprise of the London Marathon, Ride 100 (a 100 mile bike ride looping out of London) and the Swim Serpentine. And like many others, I just have the swim to complete to earn that elusive ‘Classics’ medal.

I’ve actually been signed up to swim the last two years but one year was cancelled due to the Queen’s funeral, and last year algae levels were near dangerous levels and so refunds were offered (it was two weeks before Bertie was born and I was probably undertrained so I opted out).

For me, a two mile swim is FAR. Like kinda scary far. My plan is to swim it next year with my friend Tam and give myself a decent amount of time to train for it!

For those training for Swim Serpentine this summer, or other long distance swims including Ironman, the Henley Swim events or Swim/Run hopefully this is a helpful guide for your training…

I spoke with Lara Giusti, co-founder and head chef at Veloforte about fuelling for swimming on this week’s episode of the Cook Eat Run podcast. You can listen to the episode here – and don’t forget first time shoppers can save 10% across Xmiles with code THERUNNERBEANS and for podcast listeners/repeat customers, in August you can save 10% off Veloforte with code COOKEATRUN.

How does swim fuelling differ to running and cycling?

So the joy of running and cycling is you have all these wonderful pockets to shove your energy products in, whether it’s in your running belt, hydration pack, running shorts (my current faves with double pockets) bag on your bike, So if you’re running and cycling for long enough that demands you to fuel, then easy, you shove your fuel of choice into your pockets. With swimming it’s much harder – whatever you’re going to be fuelling with needs to be in a waterproof packet, needs to be easy to either tuck it in your wetsuit or down your swimsuit, really quick to access, easy to open, and in liquid format.

What we see is a lot of people who swim tend to focus on pre fuelling and post fuelling.

Typically very long swims have aid stations or are supported, so it’s the 90min ish swims that you might want to take some mid-swim fuel like a gel. For swims under that, if you’re fuelling right in the pre and post swim, you should be absolutely fine.

Why do I get so thirsty on my swims?

There is a misconception because you’re in the water, you don’t sweat. You absolutely do sweat! And especially if in you are training in a heated pool, you will be sweating, you will be losing vital electrolytes and you won’t be necessarily as aware of that. So it’s really important to stay on top of your electrolyte load.

Pre-fuelling with electrolytes before you swim, either on their own or with some carbs in there can help with hydration. Additionally you can keep a bottle on the side of the pool and have a swig between sets. If you’re open water swimming you could think about taking a gel with electrolytes in (all the Veloforte gels contain electrolytes) or loop back to a dock with a bottle if that’s possible!

Plus having a hydration mix as part of your recovery can help avoid any post-swim dehydration.

For those taking on ultra distances you should have support boats etc that can carry your hydration and fuel. It’s alla bout planning and training your gut so that you know exactly what you need.

Should you practice while swimming?

Training your gut on the run is something I really advocate for and it makes sense that the same is true for swimming – and actually just practicing how to fuel while swimming!

If you’re planning on having a gel kind of midway through or partway through your swim, I’d suggest practising in your longer swim training, even if you’re in the pool.

You don’t want any surprises on event day. It IS hard to coordinate, treading water, opening a gel, taking it. What do you do with the packet? So shoving it back into your swimsuit or wetsuit, you’ve got to practise it and you’ve got to know how that feels when you can’t touch the bottom, and when you’re slightly out of breath. So absolutely practise it in your training. Even if you’re doing a shorter training swim, still practise the fuelling.

And where you’re going to put it – whether that is up your wetsuit sleeve, pinned to your swimsuit, or tucked in your neck if you’re wearing a sleeveless wetsuit.

Should you Carb Load for Swim Serpentine?

Even though it may feel like it, 2 miles isn’t the equivalent of a marathon swim. So whilst you want to make sure your glycogen stores are topped up by increasing your carbohydrate intake in the days leading up to your event, you don’t need to carb load quite like you do for a marathon run!

In the three days prior to your race, you want to increase the amount of carbohydrates in your meals and snacks – add an extra spoon of pasta, another slice of toast or scoop of granola, add in an extra cereal bar or bowl of fruit as a snack. Your body can only store enough carbs for 60-90 mins of exercise, so if you’re going to be close to or over that, we want to ensure your carb stores (glycogen stores) are fully topped up pre-event. Then having a carb focused meal the night before and morning of, plus a carb snack an hour or so before (depending on your event timing).

What to eat before your swim

Carb focus with a small amount of protein and some healthy fats. It should be something that you’ve eaten before and know your stomach can tolerate. No surprises on event day!

So if you love oats, have some oats, but add some peanut butter or Greek yogurt and some fruit like a banana or berries in there, plus some honey for extra carbs. if you prefer eggs, have eggs on toast or a bagel plus a banana. Have this 2-3 hours before your race. Or if you’re swim is later in the day, have a sandwich or bowl of pasta – but make sure you’ve practiced this in training!

An hour or so before your swim have a carb snack – like an energy bar or carb drink as well as an electrolyte drink. If you like caffeine – make sure to take that about 30-45 mins before you start so that it can reach peak performance mid-swim! It takes 45-60 mins for caffeine to enter your system and works for about 3 hours.

20 mins before you could have half a gel, some carb drink or half a banana if you can stomach it.

Choose foods that sit well in your stomach, that you’ve practiced in training and that you have time to digest!

Do I need to fuel while I’m swimming?

If you’ve eaten a good amount of carbs before your event, and you’re swimming for up 60-90mins, you shouldn’t need to consume any carbs on the go. However if you think it will take you longer than this, or you feel best when your carbs are topped up (I mean, who doesn’t?) then you might want to take a gel about an hour in, or every 45 mins.

Swim Serpentine 2 mile race average finish time seems to be about 1 hr 20 mins, although finishers typically take 40 mins to 2 hours to cover the distance.

How to nail your post-swim recovery

After your event the most important thing is that you really take your recovery fuelling. If you haven’t managed to take on energy during that 80 minute swim, your glycogen levels are through the floor, you’re in massive glycogen debt. So your focus on recovery nutrition needs to be carbohydrates first plus protein, ideally within that 30 minute ‘golden’ window. Plus fluids/electrolytes.

As soon as you’re out the water, warm up, have something to eat which is carbohydrate focused with protein, and restore your electrolytes either with electrolyte drink or having electrolytes in your protein recovery shake. Then, you know, that you’ve ticked that box, you’ve kick started your recovery and then you’ve got 2 – 3 hours to have a proper balanced meal.

Do you have any kind of final top tips for people taking on a swimming challenge or just kind of new to perhaps fueling for swimming?

Try the different types of fuels on offer (check out my review of the Best Energy Gels) Find one that you enjoy, that you want to fuel with, because in that moment when you’re battling a wave or even in, like in the serpentine, where there’s lots of swimmers around you, and that’s a very new experience as well. Normally, your swimming training will just be you in a lane or very few swimmers, in a lake or wherever, but having that volume of swimmers, the splash that’s going on around you, the turbulence in the water, choose, something that you’re gonna, you’re not, you’re not gonna brace yourself for fueling you’re gonna enjoy the taste of and you, and you look forward to, you know, sits well in your digestion as well. So it’s all about practice!

Don’t forget to listen and subscribe to the Cook Eat Run podcast – and use code COOKEATRUN to save 10% across all Veloforte products at Xmiles.com.