Hydration

Hydration - drinking enough fluids - is one of the single most important processes needed for optimal health and, at its most basic level, to sustain life. 

Water makes up a significant portion of our bodily makeup - specifically, around 55% for women, and around 60% for men, who genetically have less fatty tissue than women. Given this, significant changes to our fluid levels can have a major impact on our general health and wellbeing, as well as our bodyweight. 

We lose water continuously through bodily functions such as sweating, exertion and excretion (Urination), making it critically important for us to keep our fluid levels topped up by drinking.

While this so far seems pretty simple - and, for most of you staying hydrated will be far simpler than you might think - a number of common questions tend to arise when it comes to hydration, such as how much we should be drinking, why it is important to drink regularly and critically, many also want to know how to drink more without it feeling like a chore . 

How much water should we drink

Speaking candidly, it’s difficult to give a hard number around how much to drink. Our hydration levels are extremely dynamic and monitoring our hydration relies upon a series of complex calculations around our metabolism, body composition, sweat rate, relative humidity, the amount of fluid taken in from food and the temperature - to name just a few. 

Subsequently, it’s tricky to give a definitive answer on how much you should be drinking outside of “when you’re thirsty”. However we like to use a basic calculation based on bodyweight which will give you a good idea of an individual baseline; Bodyweight in KG x 0.033, eg, 85kg x 0.033 = 2.8 litres.

There are also certain special populations that may need to drink more water, or at least be more mindful of their water intake, than others. Firstly, elderly people may have a weakened sense of thirst compared with their younger counterparts, leaving them at greater risk of dehydration if fluid intake is not monitored. 

That said, it is also important to ensure that you hydrate more gradually if you’re elderly, as your kidneys may be less able to handle the filtration and elimination of water than previously. 

Children also need to stay hydrated, due to both their body temperature rising more quickly than adults, and children’s propensity to ignore hunger or thirst signals when they are otherwise engaged. This means that, if you are responsible for taking care of a child, it’s important to keep an eye on them and gently encourage them to take a drink from time to time.

Why we need to stay hydrated

Aside from, you know, staying alive, staying hydrated comes with a number of benefits. 

If you are dehydrated, you may feel weak, faint, susceptible to headaches, dizzy or confused - symptoms that can be particularly noticeable in the elderly, who are already more susceptible to this occurring. If you’re hydrated, you naturally do not feel these effects - quite the opposite, in fact. Because the human brain is around 80% water, while dehydration can affect it in a negative way, drinking enough water can improve your memory, mood and overall cognitive function. 

If you’re active, or play a sport, staying hydrated is critical for performing at your best. In fact, research suggests that your performance during exercise can be significantly hindered when you’re dehydrated by as little as 2% of your total bodyweight. Taking this further, fluid losses of 5% and above can decrease your work capacity by as much as 30%! Given this, it is little surprise that studies also suggest that the fatigue you feel towards the end of a prolonged sporting event, such as a marathon or football match, can be caused by dehydration as much as fuel substrate (e.g. glucose) depletion.  

Proper hydration, particularly when it comes from water rather than more calorific drinks, can also potentially aid weight loss. Specifically, consuming water before a meal naturally takes up space in your stomach and, through this, makes you feel more full and can prevent overeating.

Furthermore, your body can sometimes confuse thirst signals for hunger pangs, meaning that when you feel hungry sometimes it’s a drink you need instead. Essentially this means that if you’re hydrated, you may feel hunger pangs less often and therefore be better able to control your calorie intake. 

Finally, because water helps to keep your internal organs working as they should, staying hydrated also benefits healthy toilet habits. Specifically, adequate water intake may help to both prevent constipation and reduce the risk of bladder infection, kidney stones and other associated conditions. 

How to monitor hydration

There are no doubt many complex, scientific ways to monitor your hydration levels, but neither of us, given we live normal lives, are all that interested in that. Telling whether you’re hydrated can be as simple as: if you’re thirsty? Take a drink. 

If you find you don’t tend to feel thirsty all that often - or perhaps you’re too busy to take notice of thirst signals - another fairly fail-safe way to assess your hydration levels is to monitor your urine.

What I mean by monitoring your urine is assessing its colour and odour. If your urine is clear in colour (or at least pale), and odourless, your hydration levels are likely to be good. On the other hand, if your urine is darker in colour and smells a bit, then you’re likely at least a little dehydrated, and I’d advise getting some fluids in as soon as you’re able. 

How to drink more

Tips for how to drink more throughout the day: 

• Have a bottle of fluid near you at all times, although try to drink the majority of your water earlier in the day to avoid disturbing your sleep by having to get up in the night for the toilet.

• Set a timer/alarm or a goal to drink a certain amount (such as a glass or small bottle) of fluids within a certain time period, such as every hour.

• You often start each day slightly dehydrated, given you haven’t drank anything since the previous evening. Because of this, I advise beginning each day with a glass of water soon after you wake up.

• Drink a glass of water before each meal. As above, this can also help curb overeating during and after your meal as an added benefit.

• Eat more foods high in water. Fruits and vegetables, such as watermelon, oranges and cucumber, are perfect for this due to their high water content, and are also extremely high in essential micronutrients as an additional bonus.