Water: 7 Reasons Why Hydration Matters

Without water, life on earth wouldn’t exist. 

According to Wikipedia, water is ‘the main constituent of Earth's hydrosphere and the fluids of all known living organisms’. 

With the advent of air conditioning and central heating in both summer and winter months, most of us have no idea about our hydration status day to day. We also spend the majority of waking hours indoors for work, school or life, avoiding the sun, moving less and sweating less.. 

Sometimes dehydration can kick in without us even realising it.

(I’ll wait here for you to get a glass of water before continuing…)

Water is required for quite literally every cellular function in the body. This includes cell communication, hormone function, detoxification, digestion, elimination and more. 

Let’s dive deeply into some of the research on why staying hydrated matters, including:

What are the benefits of drinking enough water?

How much should I drink each day?

Is filtered water better?

How do I know if I’m dehydrated?

Fun Water Facts

  • Muscle tissue is 75% water
  • Blood is 82% water
  • Brain tissue is 76% water
  • Bones are 25% water

Couple drinking water after exercising

7 Reasons Why Drinking Water Is Important For Your Health

Water provides lubrication for the brain, spinal cord and nervous system

Dehydration can affect brain structure and cognition. Water is required for neurotransmitter function. Not drinking enough water can cloud your thinking and impair logical reasoning and decision making. Bottoms up!

Hydration tip: For a headache, try drinking a big glass of water and eating an apple. Wait 20 mins. This provides hydration, electrolytes and complex sugars, which can usually resolve simple headaches. 

Water lubricates the joints

Articular cartilage, joints and intraspinal disc spaces are approximately 80% water. Joint stiffness, pain and reduced range of motion are often linked to chronic dehydration. Dehydration can also impair fluid movement of the upper body and spine. Knees and ankles act as shock-absorbers during impactful movements like running and jumping. Long-term dehydration can affect this lower limb function, resulting in further pain and stiffness. 

Water is essential for digestion & elimination

The body has several major elimination systems which clear cellular debris and waste. These are skin, lungs, liver, lymphatic system, bowels and the urinary system. The body metabolises food, alcohol, medications, environmental chemicals and other toxins. The liver also breaks down blood cells, hormones, neurotransmitters and other bodily tissues. Everything is made, used, broken down and eliminated, and this process requires an abundance of water!

Without enough water, we can feel constipated, sluggish, tired, irritable and just downright bleh!

Water maintains blood pressure & protects the kidneys

Electrolytes (sodium, potassium, calcium) dissolve in water and are essential for the functioning of the kidneys, brain and cardiovascular system. Staying hydrated also protects the kidneys from tissue damage, and if the kidneys are impaired, the cardiovascular system can also be affected. Dehydration can also cause the blood to thicken, increasing blood pressure as the heart works harder to pump blood throughout the body. 

Hydration tip: If you suffer from high blood pressure, try increasing your water intake and see if it helps.

Water plumps the skin and oxygenates the body

Water in the lymphatic system delivers nutrients to all body tissues. This includes the skin, hair and nails. Staying hydrated can improve the appearance of the skin, and provides skin-loving vitamins like vitamin C to the skin’s surface. 

Glass jug pouring water into a drinking glass

Water helps regulate body temperature

When our body heats up, water that is stored in the dermal skin layers rises to the skin’s surface. We know this as sweating, and it is a crucial component of body temperature regulation. As the sweat evaporates, it cools the body surface. 

In sport, staying hydrated over the long-term can help build heat tolerance as fitness improves. This can help with events such as marathon running or trail hiking, where dehydration and heat stroke are serious health risks. Replacing electrolytes over the course of extended exercise is important to avoid muscle fatigue and exhaustion.

Water helps with weight loss

Water naturally supports elimination, as discussed above. And this can sometimes be a first step toward the body shedding extra weight. 

Once your liver, bowels and kidneys are well supported, you may start to feel lighter and more energised. 

Drinking water regularly can also help to crowd out less healthy snacks and drinks. Softdrinks, cordials, energy drinks, alcohol, even tea and coffee can all add to excess kilojoules which contribute to weight gain. These can disrupt your body’s hormones, energy and mood. Once you make a healthful switch to drinking water on the regular, your body will thank you. 

How Much Water Should I Be Drinking Per Day?

There’s a couple of formulas used to calculate the optimal water intake to support exercise. 

  • 1L for every 22kg of body weight per day


  • Body weight x 0.03 

Then add 500ml of water for every hour of strenuous exercise. 

Example: 65kg x 0.03 = 1.95L of water per day. A 65kg person who’s breathing, moving and thinking should consume just under 2L of water per day as a minimum. 

This of course is a guide only, for individualised health advice, consult your trusted health provider. 

How To Make Water More Interesting

I get it, drinking 2 or 3L of water each day can feel like a chore. But once you’re in a rhythm, your body adapts to feeling hydrated and you’ll notice a vital difference! 

Here’s some clever ideas to get you there:

  • Wherever possible, drink pure or filtered water to support your body
  • Start your day with a glass of water and squeeze of lemon. Before your coffee!
  • Add sliced oranges, lemons and mint leaves for flavour
  • Fresh raspberries & blueberries for a juicy twist
  • Make homemade caffeine-free iced tea - hibiscus, rosehip, lemon and ginger are all wonderfully uplifting
  • Choose a beautiful, colourful, reusable water bottle and take it wherever you go!

For a delicious, natural electrolyte drink - check out my Hydrating Blueberry Water recipe below

Young active female drinking waterIs Filtered Water Healthier?

A study by Johri et al. (2019) revealed that improved water quality had beneficial effects on children’s growth rates. 

First-world countries boast some of the highest quality water that is safe for consumption. Yet, some health risks still remain due to various environmental toxins that find their way into water supplies. 

Scientific evidence indicates that contaminants found in drinking water may have ill-health effects on humans. Most research suggests these toxins, known as endocrine disruptor compounds (EDCs), have negative impacts on our reproductive systems, hormones and fertility

These compounds include plastics, BPA, drug metabolites, glyphosate, dioxins, paint additives and phthalates. They are commonly found in commercial cosmetics, disinfectants, pesticides, processed food products and pharmaceuticals. 

EDCs have impacts on children’s health, according to an article published in the Pediatric endocrinology, diabetes, and metabolism journal. Similarly, teenagers, pregnant women and women of child-bearing age who are sensitive to hormonal changes are also at risk of suffering the ill-effects from EDC exposure. 

To ensure you avoid too much of this exposure, consuming pure, filtered water wherever possible is ideal for your health and the health of your whole family. 


As the saying goes, if you wait until you’re thirsty before having a drink of water, you’re already dehydrated. This is fairly true. 

The goal is to get ahead of your body’s thirst signalling and stay optimally replenished as much as possible. 

The body has specialised mechanisms for regulating hydration. When water is lost in body tissue compartments (extracellular space), the water from inside cells is released into these compartments to correct the osmolarity. Cells shrink in size due to the water loss, which communicates to the brain that the body is dehydrated, and a thirst signal is induced. 

We know that severe dehydration can be problematic for health, even life threatening. 

However, there’s emerging scientific evidence suggesting that even mild dehydration may cause some deleterious health effects among the general population. 

Popkin et al. (2010) posit that mild levels of dehydration can produce mood alterations and reduced cognitive function. Populations at risk include children, the elderly and those living in extremely hot climates. Alertness, visual-motor tracking, impaired short-term memory and concentration are all impacted by dehydration. 

A 2020 Japanese study assessed 55 healthy men and women for a 12-week study period. This randomised trial saw some participants consuming 2 x 550ml of water on top of their usual fluid intake. This increase in water intake resulted in lower blood pressure, assisted waste elimination and supported kidney filtration function. 

Research from the journal Sleep has identified that a good night’s sleep can help ensure you stay hydrated. The study found that people who slept 8 hours or more each night were more hydrated than those who achieved 6 hours regularly. 

This is thanks to the regulation of antidiuretic hormone (ADH) which helps maintain blood pressure and vascular resistance. ADH is released at night and helps with hydration via the kidneys. It signals whether to retain or release tissue salts to maintain appropriate hydration status. 

Three glasses of water - why hydration matterws

Simple Signs of Dehydration

Water content is lost through daily elimination, breathing and sweating. 

Whatever is lost, must be replaced by the food we eat and fluids we drink. 

Research suggests we can lose up to 2L of water per day just from breathing!

Dehydration Signs:

  • Fatigue
  • Brain fog
  • Impaired cognition
  • Irritability
  • Dry skin
  • Poor lymphatic return
  • Muscle cramps
  • Decrease urine output
  • Dry mucous membranes
  • Increased blood pressure
  • Anxiety
  • Headaches
  • Back and joint pain
  • Allergies/Itchiness

Can I Drink Too Much Water?

Most healthy adults can metabolise quite a lot of water as part of their daily routine. 

However a consequence of drinking too much water in one go, is known as water intoxication or hyponatremia. This occurs when the blood’s electrolyte levels, primarily sodium, drops dangerously low. This sudden drop causes fluids to move into tissue cells, causing the cells to expand rapidly. Intracellular swelling can be life threatening, especially if it occurs in the brain or heart.

Researchers from The American journal of medicine reports that balancing sodium together with water consumption will ensure appropriate hydration is maintained. 

Adding a ¼ tsp of sea salt to a glass of water, in states of severe dehydration (such as post-exercise) can help combat the risk of developing hyponatremia. 

For children, the elderly, or anyone with impaired heart or kidney function, it’s best to tread cautiously and drink moderate amounts of fluids throughout the day as usually recommended.


Hydrating Blueberry Water

A great electrolyte-boosting drink, for pre and post workout or enjoyed on a hot summer day.


250ml coconut water

250ml filtered water

50g blueberries

1 pinch sea salt 

1 banana


Blitz everything in a blender and enjoy.

Article References

Beszterda, M., & Frański, R. (2018). Endocrine disruptor compounds in environment: As a danger for children health. Pediatric endocrinology, diabetes, and metabolism, 24(2), 88–95. https://doi.org/10.18544/PEDM-24.02.0107

Carroll, H. A., & James, L. J. (2019). Hydration, Arginine Vasopressin, and Glucoregulatory Health in Humans: A Critical Perspective. Nutrients, 11(6), 1201. https://doi.org/10.3390/nu11061201

Corona, G., Giuliani, C., Parenti, G., Colombo, G. L., Sforza, A., Maggi, M., Forti, G., & Peri, A. (2016). The Economic Burden of Hyponatremia: Systematic Review and Meta-Analysis. The American journal of medicine, 129(8), 823–835.e4. https://doi.org/10.1016/j.amjmed.2016.03.007

El-Sharkawy, A. M., Sahota, O., & Lobo, D. N. (2015). Acute and chronic effects of hydration status on health. Nutrition reviews, 73 Suppl 2, 97–109. https://doi.org/10.1093/nutrit/nuv038

Gonsioroski, A., Mourikes, V. E., & Flaws, J. A. (2020). Endocrine Disruptors in Water and Their Effects on the Reproductive System. International journal of molecular sciences, 21(6), 1929. https://doi.org/10.3390/ijms21061929

Johnson, E. C., & Adams, W. M. (2020). Water Intake, Body Water Regulation and Health. Nutrients, 12(3), 702. https://doi.org/10.3390/nu12030702

Johri, M., Sylvestre, M. P., Koné, G. K., Chandra, D., & Subramanian, S. V. (2019). Effects of improved drinking water quality on early childhood growth in rural Uttar Pradesh, India: A propensity-score analysis. PloS one, 14(1), e0209054. https://doi.org/10.1371/journal.pone.0209054

Lau, W. Y., Kato, H., & Nosaka, K. (2019). Water intake after dehydration makes muscles more susceptible to cramp but electrolytes reverse that effect. BMJ open sport & exercise medicine, 5(1), e000478. https://doi.org/10.1136/bmjsem-2018-000478

Nakamura, Y., Watanabe, H., Tanaka, A., Yasui, M., Nishihira, J., & Murayama, N. (2020). Effect of Increased Daily Water Intake and Hydration on Health in Japanese Adults. Nutrients, 12(4), 1191. https://doi.org/10.3390/nu12041191

Ma G. S. (2019). Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine], 53(4), 337–341. https://doi.org/10.3760/cma.j.issn.0253-9624.2019.04.001

Perrier E. T. (2017). Shifting Focus: From Hydration for Performance to Hydration for Health. Annals of nutrition & metabolism, 70 Suppl 1, 4–12. https://doi.org/10.1159/000462996

Popkin, B. M., D'Anci, K. E., & Rosenberg, I. H. (2010). Water, hydration, and health. Nutrition reviews, 68(8), 439–458. https://doi.org/10.1111/j.1753-4887.2010.00304.x

Rosinger, A. Y., Chang, A. M., Buxton, O. M., Li, J., Wu, S., & Gao, X. (2019). Short sleep duration is associated with inadequate hydration: cross-cultural evidence from US and Chinese adults. Sleep, 42(2), 10.1093/sleep/zsy210. https://doi.org/10.1093/sleep/zsy210

Suh, H., & Kavouras, S. A. (2019). Water intake and hydration state in children. European journal of nutrition, 58(2), 475–496. https://doi.org/10.1007/s00394-018-1869-9
Wikipedia Contributors. (2021, December 14). Water. Retrieved from Wikipedia website: https://en.wikipedia.org/wiki/Water#Human_uses, viewed December 14 2021