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PT Reveals How You Can Use The ‘Sweat Test’ To Check You’re Drinking Enough Water

Person Drinking Water

​​As fitness competitions like Hyrox and Iron Man grow in popularity, many athletes and fitness enthusiasts face a common challenge: how to stay properly hydrated while pushing their bodies to the limit. But how much water do you really need? Enter the ‘sweat test.’

Professional trainer at UNTIL, Tomi Akande, explains: “A sweat test is a simple yet effective method used by athletes to determine their personal hydration needs, far beyond the general NHS guideline of 1.6 to 2 litres of water per day.”

Take a sweat test at home

Tomi says: “The sweat test is an athlete-approved method to accurately measure how much water your body loses after an hour of exercise – your sweat rate – to reveal how much you need to replenish during and after.

“To find your sweat rate for a specific sport, you need to do the exercise for 60 minutes at your usual pace. This starts with weighing yourself before without clothes on, going into the exercise with a controlled amount of water – 500ml for example – then weighing yourself again straight after with no clothes on after patting dry with a towel” 

Your weight difference, plus the amount of water you drank during the exercise (1ml = 1gram), will reveal your average sweat rate per hour in that specific climate. If you lose weight after the sweat test you will know how much more water you need to drink during each hour of that exercise to stay hydrated, and vice versa.

Tomi adds: “Athletes use the sweat test to make sure they lose no more than two percent of their weight from water after endurance exercise, such as a long run, as this puts your body at risk of dehydration.”

You can work out your dehydration limit by multiplying your body weight by 0.02, so if you weigh 60kg you would suffer from dehydration after losing 1.2 litres of water.

If you’re planning to take part in any endurance activity, from a 10k run to an Iron Man, it’s crucial to understand your sweat rate and how much water you need to intake per hour to avoid dehydration.

Increase hydration in hot weather

Young woman in leggings with towel on shoulders drinking water after fitness training

It’s important to remember that your sweat rate is also dependent on the temperature and humidity of your surroundings, so if you measure your sweat rate for a yoga session this will be significantly different from your sweat rate for a hot yoga session – which would be much higher.

If you’re going on holiday to a hot country and plan to exercise there, this means you should increase your water intake to avoid dehydration as your sweat rate would be higher than usual.

When should I drink water?

It should go without saying, but you should always make sure you’re properly hydrated before exercising, whether that be a gym session or a marathon, by keeping track of your day-to-day water intake. 

Drinking extra fluids during your workout is a priority though to avoid reaching your dehydration limit. In any case, drinking fluid after exercise will help to replace any hydration lost from sweat.

Tomi adds: “Dehydration can play a major role in our body and brain function. If you’re doing high-intensity exercises regularly, ensuring your water levels are correct is important. 

“A sweat test can be a great way to get started whether you’re a total beginner or a professional athlete. Getting ahead of the curve can ensure you kickstart your fitness goals on the right foot and minimise future risks of burning out.”

For more information or to find out how you can train with a pro like Tomi, visit: https://www.until.co.uk/find-your-pro