What should I eat during a marathon swim?

Jelly Babies, caffeine gels or peanut butter sandwiches? Swimming coach Cassie Patten and veteran long distance swimmer Colin Hill are your guides to refuelling during a marathon swim.

“I have recently signed up to a Windermere one way. This will be my second marathon distance swim. During my first swim I had a decent breakfast and an energy drink before starting and then only had a drink of water from the boat nearly 8K in. How should I fuel my Windermere swim? What drinks, snacks, treats, and how often should I feed?” Billy

Great question! Firstly a little disclaimer, I am not a trained nutritionist and I can only tell you what worked for me on my swims. I used to carry carb gels when I was competing. I would tuck them in the back of my swimsuit and rip into them when needed in the race. I would also have a bottle of watered-down Powerade passed to me at feeding stations. I used to water my drink down as I found taking it neat would give me a stitch.

The longest it would take me to race a 10K would be two hours so I could get away with not refuelling if the race dictated, if I had loaded well beforehand and was well hydrated. At 10.5 miles long, Windermere is further than the 10K distance I used to race, so I reached out for some expert advice. Colin Hill is a veteran long distance swimmer and now open water swimming guide based at Ullswater in the Lake District. He gave me the following in-depth information…

Colin Hill on fuelling up for your marathon swim

I’ve guided hundreds of people on length of lake swims and although everyone is different, generally people tend to feed on warm carbohydrate drinks. In my experience, I have found that Maxim is a favourite with many channel swimmers. To take it you can pre-mix a double strength carb drink, then you add enough hot water to get the right strength for your taste.

I would then recommend swimmers dive into caffeine gels later into the swim if they need a boost. Just remember if a swimmer doesn’t drink a lot of caffeine normally they are quite strong so go easy on them. You can also feed on sweet treats such as Jelly Babies, Haribo or Milky Ways as they are easy to eat and do not get stuck in your teeth.

On two-way swims people do need something more substantial such as peanut butter, jam or cheese sandwich. However warm carb/energy drink, gels (you can buy gels that you don’t need to have with water) and treats are normally fine for a 10 mile swim.

Finally it is recommended that the person builds up with 5K, 5 miles and 10K swims to practise feeding and times to see what works for them, rather than leave it for the big swim.”

A final word from Coach Cassie

I hope that answers your question. The only other point I would add is for anyone who might be swimming a long swim without a canoeist by their side. It is important to consider where you will put your feeds. If swimming in a wetsuit there is not a lot of room, so tuck them up your wetsuit leg by your ankle. Getting them out is a skill that needs practising! Also think about food that is easy to open with cold hands – and remember to take any rubbish home with you.

Cassie Patten won bronze in the first ever Olympic 10K marathon swim, in the Beijing 2008 Olympics. She now runs WaveCrest Swimming, the South West’s premier swimming coaching company.

Colin Hill is an International Marathon Swimming Hall of Fame inductee, an English Channel soloist and the first UK male to officially complete the Ice Mile. He loves coaching swimmers from beginners to very experienced at Ullswater Swim Place.

Read more tips from swimming coach Cassie Patten.