Hydration testing is something you can do throughout the year at different points as the weather changes. It’s a great way to stay on top of how much you should be drinking to avoid dehydration and hyponatraemia.
It’s recommended that we avoid water loss exceeding 2% of our bodyweight. So, if you weigh 70kg that would be the loss of 1.4kg of water.
Here’s the test:
- Take a standard session you might do a 1-hour turbo is ideal. Weigh yourself before (naked).
- Drink a controlled amount of water over the turbo – let’s say 1 sports bottle (500ml). Ensure you drink all of this over the session, oh and that you’ve dressed yourself again haha.
- After the hour session before consuming anything else, undress, wipe yourself down with a towel and weigh yourself again.
This number at the end will let us know your average sweat rate per 1Hr in those conditions. It’s important to remember this number relates to the intensity of that session and the ambient temperature. You will always sweat more indoors as there is no wind cooling.
With that loss add the 0.5kg from the bottle you drank. This now tells you your sweat loss per hour. So, if you lost 0.5kg you’ve lost in total 1kg over 1 hour.
You can use an outdoor ride to test this too BUT ensure it’s still only an hour if you go for longer then you will start eating food or gels, you will also be expending large amounts of glycogen that will also affect the results.