Swimrun – 4 Tips To Stay Hydrated

Swimrun is a demanding sport, its very easy to get dehydrated while participating. Running in your wetsuit will increase perspiration and swimming in cold water also increases your rate of fluid loss.

Swimrun.com is not responsible for an individuals hydration and nutrition planning and this piece is meant as an opinion piece rather than formal advice. Athletes must do their own research.

Throughout this article, we will talk about something called hyponatremia. This is a fancy medical word for having low blood sodium which is something we should avoid.

Here are 4 tips to stay hyrdrated:

Cup, bladder or soft flask?

Most Swimrun races are cup free. This means you will need to carry some form of collapsible cup to fill up from aid stations or a hydration system. For longer races, carrying a soft flask rather than a cup is a better option. It means you can sip on your replacement fluid better and stuff it in your wetsuit for swim sections. You can’t carry fluid with a cup. We have seen some participants run with a water bladder, also fine but unnecessary weight to run in and additional drag in the water. A soft flask is the way to go.

Start in a state of hydration

It’s a moot point in endurance sports, but in Swimrun, starting well hydrated is sensible. Over-hydration or hyponatremia from drinking too much fluid is something to be aware of but not too overly worry about – you need to have drunk a huge amount to get in that state. Sipping and drinking to thirst will keep you well hydrated.

Electrolyte and salts

Hyponatremia can be caused by excessive sodium loss caused by sweating. There are numerous studies of ultra runners finishing races in this state (this study claims up to 30%). There is very little data out there on Swimrun but you could expect that number to be even higher. Taking on electrolyte is important and something you should practice in training.

Post race treat

Put something incredibly naughty in your bag. We have all been there…crossed the finish line to be greeted with tepid water. Chuck something high sugar in your bag such as a can of coke or milkshake.