Healthy Hydration Myths: 3 Common Myths and Facts

par Elizabeth Harris on 15 octobre 2024

Feeling thirsty? That’s a sign you’re already dehydrated… or so everyone says.

There are countless myths around hydration that we just accept as facts. But are any of them actually true? Here are 3 top hydration myths and the facts about hydration you need to know.

1. Hydration myth: If you’re thirsty, you’re already dehydrated

A common hydration myth goes like this: if you’re feeling thirsty, then you’re already dehydrated.

While feelings of thirst are a sign of dehydration, this is an overly simplistic view of the problem. In fact, feelings of thirst can be influenced by a wide range of factors beyond your body’s hydration levels.

Thirst is controlled by a complex sensory system in the body - similar to sight, hearing, and touch.¹ While feeling thirsty is a good indicator that you need to drink a glass of water, research shows that perceptions of thirst - including mouth dryness and stomach emptiness - can happen even when you’re fully hydrated.² Thirst receptors in the mouth are also influenced by cold, which may be one of the reasons you feel more satisfied after drinking a cold glass of water or soda when you’re really thirsty.³

Feeling thirsty can also be caused by a range of different chronic conditions. For example, people with diabetes may experience feelings of thirst and dry mouth, regardless of their hydration status.^4,5 Research shows some medications can also cause increased feelings of thirstiness.⁶

The truth is, feeling thirsty can indicate you need to drink some fluids, but it doesn’t necessarily mean you’re already dehydrated. The reality is much more complex than the myth suggests.

2. Hydration myth: Coffee and tea dehydrate you

It’s commonly accepted that coffee and tea don’t hydrate the body because of their caffeine content. You’ve probably heard people saying that coffee is a diuretic - meaning it makes you pee more frequently - so it dehydrates rather than hydrates the body.

In reality, the diuretic effect of caffeine has been hugely overstated. A review published in the Journal of the International Society of Sports Nutrition found that moderate caffeine consumption doesn’t have a diuretic effect on the body.⁷ Caffeine only has a diuretic effect if it’s consumed in excessive and impractical doses, which the regular coffee or tea drinker is very unlikely to reach.⁷

The doses of caffeine you’d usually find in standard servings of coffee, tea and caffeinated soft drinks don’t have any diuretic effect, according to the research. So, you can happily drink coffee and black tea, without any dehydration worries.

3. Hydration myth: You need to drink 6 to 8 glasses of fluids per day to stay hydrated

Most guidelines state you should aim to drink around 6 to 8 glasses of water a day to stay hydrated.⁸ While this is a good rule of thumb, it doesn’t tell the whole story when it comes to hydration.

The truth is, your optimal fluid intake can vary depending on a wide range of factors.^9,10 This can include:

Your genetics
Your age
Your weight
Your exercise level
Your sweat rate (how much you sweat)
Your environment (where you live)

For example, if you live in a hot, dry climate, you exercise regularly and you sweat a lot, you’ll probably need to drink more fluid to stay hydrated compared to someone who’s not exercising at all.

As a starting point, try to drink 35mL of water for every kilogram you weigh.¹¹ For example:

If you weigh 72kg (159lbs), aim to drink around 2.5l of water per day
If you weigh 85kg (188lbs), aim to drink around 3l of water per day
If you weigh 100kg (220lbs), aim to drink around 3.5l of water per day

The truth is, if you want to stay hydrated, you’ll need to adapt how much water and fluids you drink each day depending on your lifestyle, environment, and genetics.

Feeling thirsty? Try a tastier way to hydrate

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Every scoop of our strawberry kiwi and raspberry lemonade blends are packed full of electrolytes and powerful antioxidants. enhanced electrolytes+ also includes fermented beetroot powder, Melorun® (a melon extract), vitamin D3 and guava leaf extract (standardized to 4% zinc). Together, this formula will help maintain normal electrolyte balance, proper muscle function and tissue formation, support immune function and provide a source of antioxidants.

Now, who's thirsty?

Date modified: February 14^th, 2025

References

Zimmerman CA. The origins of thirst. Science. 2020;370(6512):45-46. doi:10.1126/science.abe1479
Armstrong LE, Giersch GEW, Dunn L, Fiol A, Muñoz CX, Lee EC. Inputs to thirst and drinking during water restriction and rehydration. Nutrients. 2020;12(9):2554. doi:10.3390/nu12092554
Gungor S, Tosun B, Candir G, Ozen N. Effects of cold spray on thirst, frequency of oral care, and pain of general surgery intensive care unit patients. Sci Rep. 2024;14(1):9997. doi:10.1038/s41598-024-58199-0
Thirst. NHS Inform. Updated January 7, 2025. Accessed February 19, 2025. https://www.nhsinform.scot/illnesses-and-conditions/nutritional/thirst/
López-Pintor RM, Casañas E, González-Serrano J, et al. Xerostomia, hyposalivation, and salivary flow in diabetes patients. J Diabetes Res. 2016;2016:4372852. doi:10.1155/2016/4372852
Eng SH, Jaarsma T, Lupón J, et al. Thirst and factors associated with frequent thirst in patients with heart failure in Spain. Heart Lung. 2021;50(1):86-91. doi:10.1016/j.hrtlng.2020.08.002
Antonio J, Newmire DE, Stout JR, et al. Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr. 2024;21(1):2323919. doi:10.1080/15502783.2024.2323919
Water, drinks and hydration. National Health Service UK. Updated May 17, 2023. Accessed February 19, 2025. https://www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/water-drinks-nutrition/
Armstrong LE, Johnson EC. Water intake, water balance, and the elusive daily water requirement. Nutrients. 2018;10(12):1928. doi:10.3390/nu10121928
Why it’s important for you to drink water and stay hydrated. Good Food Is Good Medicine. Published July 21, 2022. Accessed February 19, 2025. https://health.ucdavis.edu/blog/good-food/why-its-important-for-you-to-drink-water-and-stay-hydrated/2022/07
Balaghi S, Faramarzi E, Mahdavi R, Ghaemmaghami J. Fluids intake and beverage consumption pattern among university students. Health Promot Perspect. 2011;1(1):54-61. doi:10.5681/hpp.2011.005