How the Human Body Uses Water15 May 2019 | Facts & Curiosities
We all know that water is the most important element on our planet. Every living thing, from tiny cyanobacteria to giant blue whales, needs water to survive. Life would not exist without water, and wherever there is water you will find life.
It’s common knowledge that water is vital for survival. But you might be surprised to learn just how intrinsic water is to almost every one of your body’s everyday functions – from breathing to digestion to the tiniest of muscle movements. Here’s a quick guide to how the human body uses good old H20, 24/7/365, and how to take advantage of that to maximise your watery wellbeing!
A few fascinating facts to “wet” your appetite
- Water plays a massive part in our moods and in our body’s ability to release energy from food. Feeling tired, lethargic, a bit low? It could be something more serious, but there’s a pretty good chance you’re just dehydrated.
- Brain cells are 80% water. For an average person, a 2% reduction in body water levels is enough to cause a 20% decrease in mental and physical performance. That’s the same as drinking four shots of alcohol, or twice as much as suffering from a bad hangover (and considerably less fun than either)!
- We say for an average person, because there’s evidence that some athletes have managed to “hack” their metabolisms through intensive training. World-class sportsmen can often perform incredible physical feats while suffering from levels of dehydration that would debilitate lesser mortals. Legendary long-distance runner Haile Gebrselassie once dropped 9.8% of his body mass running the Dubai marathon – a race that he won with a record-breaking time of 2:05:29. A similar study found that the top five finishers in South Africa’s gruelling Iron Man triathlon all shed around 8% of their body weights – One even lost 11%!
- That’s even more incredible when you consider that the body is around 60 per cent water – so losing 11% body mass means shedding almost twice that in terms of water content. Plus, if all this talk of athletic achievements is making you cast guilty looks at your running shoes, you can tell yourself you’re not overweight – just well hydrated.
Now for the Science – How the Human Body Uses Water
Your body uses water in almost every one of its parts and processes. Cells, organs, bones and tissues all rely on it – from transporting the building blocks of biology to evacuating the waste products left behind. Water lets us regulate our temperature, digest our food and transmit electrical signals to control our organs and muscles. Let’s dive in!
Water Regulates Your Temperature
Lashing rain, howling winds and temperatures you can count on the fingers of one hand. That’s right: it’s British summertime again. And while you huddle optimistically over a sputtering barbecue in your winter woollies, your body is working hard behind the scenes to keep your core temperature hovering around its sweet spot – within a degree or so of 37 degrees Celsius.
One of the main ways it does so is by directing the flow of blood around the body. By opening veins and arteries close to the skin, your body can radiate heat into the surrounding air to cool you down. Conversely, by directing flow deeper into the body, it insulates the blood under layers of protective fat and tissue to trap and recycle the maximum amount of warmth. Fun fact, this process is the reason you turn red when you’re hot, and pale when you’re cold!
Water is essential for this process because it’s the main ingredient in sweat. Evaporating sweat carries heat away from the body many times faster than air alone – which is also why it’s much harder to stay cool in humid environments, where sweat struggles to evaporate. Blood is also around 50% water, and the part of your brain that regulates the whole thing is about 80% good old H20 – so water is key to every part of the process.
Water Protects Your Tissues, Spinal Cord, and Joints
Ever wondered why your bones don’t grind together when you walk around? No? Well – fair enough, but it’s also thanks to our old friend water! You have a bag of something called “synovial fluid” in between each of your joints, which acts as a cushion to protect and lubricate the ends. It absorbs the knocks and shocks of everyday life like the soft sole of a shoe; helping to prevent a range of ailments from regular strains and sprains through to osteoarthritis. Even your bones are 30% water!
Water Lets you Digest Food
Most people associate the stomach and bowels with digestion, but it starts in the mouth with saliva. No prizes for guessing that water is the main component, mixed up with a few key enzymes and electrolytes. Water also plays a major role in the production of stomach acid, the movement of food through the body, and of course its eventual exit (of which we will spare you the details)! Ingesting water before, during or even after a meal is proven to improve your uptake of vitamins and nutrients while helping the kidneys to filter out what your body can’t use. In fact, almost every single chemical reaction that goes on in your body uses water to balance the reagents and keep things ticking along smoothly, and the part of the brain that controls it (the pituitary gland) – you guessed it, 75% water.
Kind of crazy when you stop to think about it, right?
Handy Hydration Hacks for healthier, happier humans!
So now that we know we’re mostly water – or to use a wonderful turn of phrase from Paloma Faith, “we’re pretty much just cucumbers with anxiety” – what do we do with this information? Well, Hero Labs has got your back – here’s our handy hydration hacks for healthier, happier humans. Hurray!
Water for weight loss
There’s mounting evidence that drinking water before a meal helps to occupy space in the stomach and bowels, meaning we trigger our “satiety response” sooner and don’t need as many calories to feel full. In one study, participants who drank a glass before dinner lost 40% more weight than those who didn’t over a period of three months. Drinking water also seems to raise our metabolisms and make us burn more calories for the subsequent 90 minutes or so, even while sitting still. And on top of that – there’s some evidence that it reduces our appetites for sweet things overall, so a glass of water is a weight-loss triple whammy.
Water for mental performance
Got an exam or an interview coming up – or even a hot date that you really want to impress? Make sure you’re well hydrated, because water has a huge impact on your mood and cognitive performance. Maintaining a good level of hydration has been shown to improve memory, attention, problem-solving and coordination. There’s evidence that it helps us stay calmer under pressure and reduce anxiety. It’s even been linked to happiness and a reduction in negative, depressive thinking. But perhaps the strangest fact, brought to you by researchers from the University of Twente in Holland, is that we do our best thinking when we desperately need to pee! It’s a risky strategy, but maybe you should try downing five glasses of water before your next big life event as these participants did. Science says you’ll make better decisions!
Water for physical performance
We’ve talked about how water improves the uptake of nutrients and facilitates their transport around the body. When exercising, our bodies are under increased strain and rely on this transport mechanism to deliver fuel and remove waste products from the muscles. A key waste product is lactic acid, and it’s responsible for the “burn” that we feel when exercising hard – eventually becoming pain, and putting a limit on our activities. But lactic acid is soluble in water, so the more hydrated you are the more dilute it is and the longer you can perform.
If you’re training for strength, you’ll know that new muscle is formed through a process of “tear and repair”. The “protein synthesis” mechanism that governs this relies heavily on water, so strength gains rely not only on repeated exercise but also on adequate hydration. Many athletes use isotonic drinks to maximise their hydration – meaning they have exactly the same “osmotic pressure” as blood, and therefore hydrate the body better than water itself. You can spend a fortune on specialist isotonic formulas, but we recommend just making your own from fruit squash, plain water and a pinch of salt. It really is that simple!
Water for Beauty
We’re usually pretty sceptical when it comes to claims about cosmetics, but there’s a decent enough body of evidence behind the idea that well-hydrated people tend to have better skin and hair. Our cells are mostly water, so maintaining a good level hydration keeps them plump and tends to smooth out blemishes and wrinkles. You may not even need to worry about drinking it – one Japanese study found that misting plain water onto participant’s faces was at least as effective as several leading anti-ageing creams! Another study found that drinking 500ml of water at a time promotes blood-flow to the face – making us appear healthier, and mimicking the subtle changes that occur when we look at someone we fancy (!). Another tick in the “hot date” box, then? Either way, plenty of good reasons to stay hydrated.
If this article has you looking at water in all kinds of new ways, perhaps you’d like to treat your humble home plumbing to a smart leak detector from Hero Labs. Sonic by Hero Labs is a clever little box that monitors your whole home for leaks, reducing water waste and protecting your possessions too. It’s even smart enough to tell you which appliances use the most water so you can stay on top of your bill, and help to protect the planet as well. Water’s wonderful stuff, so show it some love with Sonic!