Water is an essential component for all known life. It plays a role in every process that occurs within every living cell, including the ones that make up a human body, and this means that water plays a role in everything your body does to keep you alive. Water helps us to regulate our body temperature, maintain optimal cognitive function, aids our digestive, cardiovascular, and our immune systems, helps regulate organ function and lubricate our joints, and so making sure we drink enough water enables our body to stay on top of all of these things. Staying hydrated can also help protect us against certain health issues such as kidney stones, UTIs and some skin conditions. When thinking about how important water is, just remember that over 60% of you is made up of it!
The good news is that hydration is easier to achieve than you may think. While drinking water is the ideal way to stay hydrated, everything you drink will hydrate you in some way. There is a bit of a misconception that things like coffee and tea dehydrate you, but this is not actually true. Caffeine increases urine output when you first start using it, but this increase is less than the liquid contained within a standard cup of coffee, and it stops happening once you habituate to caffeine intake – something that most of us have done already! Espresso shots probably aren’t going to count much towards your hydration status but a couple of cups of coffee and/or tea per day are completely legitimate ways to meet your hydration needs (just don’t use them as a substitute for sleep!).
Some foods also help hydrate us, generally any fruit or vegetable will contain water that will contribute to our hydration, particularly things like cucumber, celery, melon, and citrus fruits.
Generally, drinking between 1.5-2 litres of water should be enough depending on your size, age, and gender. Because of this, other recommendations like 25ml per kilogram of bodyweight have been suggested and will likely get you somewhere closer to ideal. With that being said, daily water consumption requirements for optimal hydration can vary quite a lot - everyone is different - so the most effective way to stay hydrated is to drink a glass of water when you feel thirsty. Signs of thirst include a dry mouth, a headache, cramps, and tiredness amongst other symptoms. Noticing the colour or your urine is also a good indicator, if it’s dark you’re likely dehydrated and if it’s light in colour or clear*, you’re probably adequately hydrated.
*Note that your urine is ideally not perfectly clear. Perfectly clear urine is a sign of overhydration, there is such a thing as too much of a good thing!
The more active you are, the more you’re going to sweat and so the more water you’re going to need to stay hydrated. If you’ve just hit a workout, gone for a run, or played a game of sport then you’ll probably need to drink more water during or after the period of exercise. Staying hydrated is also particularly important as we age, as dehydration can lead to dizziness and falls, which can be dangerous for older people. Drinking around 500ml per hour of exercise is a good start, though this may go up many times over if you’re larger and/or training in the heat.
What Are Electrolytes?
You’ve probably heard of electrolytes and know that they’re somehow important for hydration, but what are electrolytes and how do they help us stay hydrated?
Electrolytes are electrically charged salts that our cells use to retain and balance water within our bodies, along with assisting with cellular signalling (including signals related to muscle contraction and relaxation). Some of the most important electrolytes are potassium, calcium, magnesium, and sodium. Because they’re used by our bodies as salts, we consume theses minerals when they’re bonded to other elements, so they come in the form of things like potassium sulphate, sodium chloride, or magnesium oxide.
When we sweat, we don’t just lose water, we lose electrolytes (this is why sweat is salty). This makes it harder for our bodies to use water we do drink during this time, and it can make things like cramps far more likely. This is why you often see football players going down with cramp when matches go to extra time, as they’ve been sweating for 2 hours and are low on electrolytes. A 2007 study published in Medicine and Science in Sport and Exercise (1) found that electrolyte-based drinks were more effective at hydrating people than water alone, and that athletes who drank electrolyte-based drinks were able to maintain higher levels of performance for longer than when they drank just water. These findings were even more pronounced during warm weather.
You can replace lost electrolytes through things like carbohydrate-containing isotonic sports drinks if you’re exercising for around an hour or more. If you’re exercising for a shorter duration than this, however, or otherwise would like a lower calorie option, you can look to electrolyte-only supplements such as Awesome Electrolytes. For many these are a great alternative as they offer the necessary number of electrolytes and a great refreshing taste for just 20 calories and 33p per serving meaning you can get your calories from your preferred sources while still staying fully hydrated, therefore protecting both your health and your performance levels.
1 - Exercise and Fluid Replacement, Medicine & Science in Sports & Exercise: February 2007 - Volume 39 - Issue 2 - p 377-390. doi: 10.1249/mss.0b013e31802ca597.