How Much Water Do I Need To Drink?

James Cooper

June 19, 2023

To optimise performance inside and outside the gym the most important thing you can do is make sure you’re hydrated.

How Much Water do I need to drink?

To optimise performance inside and outside the gym the most important thing you can do is make sure you’re hydrated.

What most people don’t realise is being over-hydrated can be just as detrimental to your performance as being dehydrated.

So how do we go about creating the perfect formula to make sure you’re performing at your best?

Dr Andy Galpin who is a professor at California state university and trainer to many NFL players, UFC fighters and Olympians has come up with the following formula for water intake.

On a day where you are resting you should take in half an oz of water per pound of body weight.

So if you weigh 220 pounds you should have 110oz of water i.e. 3520 mls of water per day. 1 fluid oz is equal to 29.6 MLS

On the days you train you will have to drink more water. This is how you work out how much more to drink after or during your training session.

You should be drinking 125% of what you’ve lost during training. i.e. if you lost 1000g of water you need to have 1250mls of water to rehydrate. This can be during and after training.

How do you know how much water you lose during training?

Weigh yourself in your underwear before training, then weigh yourself after training in underwear dried off.

You must equate for any water drank during the session.

If you’re 1kg lighter after but drank 750mls of water it means you’ve lost 1.75 Kg of water i.e. 1750mls of water.

Remember we want to drink 125% of what you’ve lost during training.

125% of 1750mls = 2187mls to drink during and after training.

The best speed to do this (so you don’t get bloated) is 2mls per kg of bodyweight every 15mins.

If you weigh 100kg that’s 200mls every 15 mins.

Does Coffee dehydrate you?

The answer is no. Coffee will rehydrate you. Caffeine itself dehydrates you but coffee contains plenty of water.

If you were to have a pure caffeine tablet itself without water then this will dehydrate you.

This is important to note as you must count all liquids; protein shakes, coffee and squash towards your water intake.

Practice sweating

One of the best ways to increase endurance is to get better at sweating.

Overheating during exercise will reduce performance during training so your body will cool itself down by sweating.

Sweating itself will not cool you down. When the sweat evaporates off your skin that is what cools you down.

Therefore, when you are training hard allow the sweat to evaporate rather than always wiping it down!

You can improve your sweating efficiency and your bodies’ ability to cooling itself down by making it heat adapted.

The easiest way to do this is by using the sauna regularly.

20 minutes 3-4 times a week is best.

What’s best to drink During training?

When you sweat you are not just losing water you’re losing mineral salts. In particular sodium and potassium.

With improper mineral balance your cells can’t work efficiently. Your cells need a certain balance of these minerals inside and outside the cells to pass signals to one another. It does this by voltage gated channels.

For the perfect drink, you want a ratio of sodium to potassium of 1 to 3.

Coconut water is my favourite but has a ratio of 1 to 5 so just add a pinch of salt and that will bring the sodium content up to around 1 to 3.

Carbohydrates will further help hydration during training by drawing water into the cells.

The best source of carbohydrate is branched cyclic dextrin. It’s a high molecular weight carbohydrate that does not cause any bloating as has a fast gastric emptying time i.e. leaves the stomach quickly. www.tb-jp.com sell an excellent product.

You want to have around 20g of carbs per 15 minutes of training. So in an hour training session you should have 80g of carbs.