Alcohol And Hydration

February 02, 2020

Alcohol And Hydration

by our Sports Nutritionist Kate Shilland

It’s no revelation that being well hydrated is critical for health and performance. Every cell, tissue, and organ in your body relies on water to work properly; without sufficient water, bodily functions are compromised and we suffer as a result. In fact, as little as 2% dehydration can negatively impact both mental and physical performance. So, it’s really important that we know how to avoid it and stay hydrated.

This is particularly relevant over the festive season when alcohol generally flows a little more freely as booze is one of the quickest routes to dehydration.

Why does alcohol lead to dehydration?
Alcohol is a diuretic, which means it makes the body lose more water than usual. It blocks the production of vasopressin, an anti-diuretic hormone which prevents the loss of water by helping the kidneys reabsorb it into the body, reducing urine output. Blocking vasopressin, therefore, triggers the production of urine and causes those increased toilet visits on a night out. As a consequence, the body’s carefully maintained fluid balance becomes disrupted as you expel fluid at a greater rate than you consume it. In fact, for every 1g of alcohol drunk, urine excretion increases by approximately 10ml.

Alcohol can also increase your heart rate and widen blood vessels in your skin which triggers increased perspiration and further impacts hydration.

So, how do we prevent this? Here’s our before, during and after guide to help prevent hydration going down when the booze goes up.

First things first: Make sure you’re hydrated before you start. If you’ve been training during the day, focus on rehydrating fully before you start drinking (checking the colour of your wee is the easiest guide – see below). A Bamorganic protein shake post-training is a great option as milk is an excellent way to replace fluids and electrolytes essential for rehydration.

When you drink, both the liquid and alcohol contents of the drink pass through your stomach lining and small intestine into the bloodstream. If you drink on an empty stomach, alcohol will be absorbed into the bloodstream more rapidly so it’s a good idea to eat before you drink alcohol.

Drinking water along with alcoholic drinks can help to prevent dehydration. The increased toilet trips mean that water is flushed out faster than alcohol is processed so your blood alcohol concentration (BAC) increases significantly and dehydration becomes a problem. It may seem counter-intuitive to drink more when you’re already drinking lots of fluid and needing frequent wee stops, but regular sips of water in between drinks are what you need to keep yourself hydrated.

Unfortunately, switching to alcoholic drinks with less volume doesn’t reduce the need to wee. Whether you’re drinking pints or doing shots, it’s the diuretic element of the alcohol which is key to producing the urine rather than the volume of the fluid.

Plan ahead. Before you go out, leave a big glass of water and an electrolyte sachet/tablet on the side for when you get home. Electrolyte replacement solutions are ideal for helping to replace the sodium and potassium that are depleted through alcohol consumption. They deliver electrolytes in the same concentration as are found in the body which means that they are absorbed quickly. Restoring this balance within the cells aids fluid retention and therefore improves hydration whilst you’re sleeping. This will help to relieve nausea and headache associated with bad hangovers.

The Morning After:
Even if you feel fine the morning after, alcohol has lasting effects that will reduce your ability to function at your best the next day. Numerous studies show that performance is impaired the day after drinking (dependent on the quantity consumed), body temperature control is impacted and oxygen and nutrient delivery to muscles is reduced. Alcohol is also thought to suppress the anabolic response in skeletal muscle which then reduces post-exercise muscle protein synthesis, impairs recovery and hinders adaptation to training.

All in all, reason enough to keep hydrated and avoid mixing your drinks with your training. Taking the steps above will hopefully help to keep you hydrated and training well throughout the festive season and don’t forget that Bamorganic is one of the easiest and tastiest ways to rehydrate.


• Sport England website. ‘Who plays sport?’ Sport England research, accessed 30/11/15. Available at:

• Susan M. Shirreffs, and Ronald J. Maughan; Restoration of fluid balance after exercise-induced dehydration: effects of alcohol consumption; 01 OCT 1997

• Eggleton M. G.The diuretic action of alcohol in man.J. Physiol. (Lond.)1011942172191

• Roberts K. E. Mechanism of dehydration following alcohol ingestion. Arch. Intern. Med.1121963154157
• Cheuvront, S.N.; Kenefick, R.W. Dehydration: physiology, assessment, and performance effects. Compr Physiol 2014, 4, 257-285, doi:10.1002/cphy.c130017.

• Parr EB, Camera DM, Areta JL, Burke LM, Phillips SM, Hawley JA, et al. (2014) Alcohol Ingestion Impairs Maximal Post-Exercise Rates of Myofibrillar Protein Synthesis following a Single Bout of Concurrent Training. PLoS ONE 9(2): e88384.

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