How a simple Sweat Test can help you avoid triathlon dehydration…
In this week’s blog, I want to introduce you to the secret of triathlon race-hydration, which is… knowing your own personal sweat rate. This is vital because your sweat rate has a direct impact on how much you need to drink during a triathlon. We are all different and therefore require different amounts of fluid.
You might be reading this blog and thinking: “What’s the big deal, I’ll just swig my bike bottle when I’m thirsty.”
That’s fair enough, but it’s actually very difficult to listen to your thirst when you’re in the middle of a triathlon, or even when following a triathlon training plan. The chances are you’ll perform better if you drink according to your personal sweat rate. I’ll explain how to do this below.
Three Reasons to Get Your Hydration Right
- Studies have shown that even a small amount of dehydration can have negative effects on athletic performance and predispose you to heat stress.
- Dehydration slows your rate of gastric emptying (the speed at which your gut processes stuff) and puts you at greater risk of gastrointestinal distress (a bad tummy).
- Hyponatremia. This is where the sodium (salt) levels in your blood become too low. This can be caused by either losing too much sodium through sweat or by drinking so much that the existing sodium in your blood becomes too diluted. Mild hyponatremia can cause bloating, dizziness and sickness.
Why Is Triathlon Hydration Important?
- We all sweat at different rates during a race and therefore need to drink different amounts in order to rehydrate
- Every race presents different environmental and physical demands which lead to different sweat rates
How To Use Sweat Test Results
Once you know your own sweat rate, you can use it as a guide to how much you should drink on race day. For example, if you sweat 500ml per hour in your test, that’s roughly how much you should aim to replace through drinking (little and often) during your race. In reality, you’ll struggle to absorb as much fluid as you sweat out. Therefore you should practice your hydration strategy in training to get an idea of how much fluid you can handle versus your hourly sweat rate.
The sweat test instructions are below… You should also check out our IRONMAN nutrition plan blog about sodium and carbohydrate requirements for race day. Good luck!