Since Stanley cups and Yeti water bottles became status symbols – no self-respecting Pilates princess would be seen without one beside their reformer bed – we've increasingly become a nation obsessed with hydration.
Which is handy, given that we're in the midst of a heatwave, we're about to be inundated with messages to drink more water. From signs on the tube telling us to carry water with us in hot weather, to our exercise instructors imploring us to stay hydrated if we’re working out when it's warm, our water consumption has become another wellness box to tick.
© Getty ImagesHow much water do we really need?
Traditionally, we're told eight glasses of water per day is the gold standard. But what kind of glass? And surely it depends on factors such as our size, how much activity we're doing, and with summer on the way, how hot it is outside?
Christopher Harris, a hydration expert (how do we get such a job?) who works with the health calculator website Calculating.com – a platform that helps you work out wellness sums, from how much sleep you need to how many calories you burn walking – says there's an easy way to figure out how much you should actually be drinking.
He explains that as a baseline, we should drink 30ml to 35ml of water per kilogram of our body weight per day. "This formula scales with your body and immediately gives you a more relevant number than a generic daily target ever could," he says.
© Getty ImagesFor the non-mathematically minded among us, to use the formula, you multiply your weight in kilograms by 30 for an estimate, or by 35 if you tend to be more active or live in a warmer climate. The result is your approximate daily water target in millilitres.
Heatwave drinking
That said, there are times when we need to increase our water intake, including in hot weather and when we're working out, due to the water we lose when we sweat. Christopher recommends adding an additional 500ml to our intake for every 30 to 60 minutes of moderate exercise.
Hot days see our body use our hydration reserves quicker, sweating to regulate our core temperature. On these occasions, add an extra 500ml to one litre of your daily intake.
When we're travelling, we need more water, too. The cabin air on planes has low humidity, which causes the body to lose moisture more quickly than it would on the ground. To combat this, drink one glass of water roughly every hour during your flight.
© Getty ImagesHydration heroes
If you're feeling particularly parched, there are ways to supercharge your water:
Electrolytes
Available via luminous drinks such as Powerade, or powder sachets and tablets that you add to water, electrolytes are having a moment, with searches up 755%, according to Boots.
The essential mineral salts carry an electric charge, which helps the body regulate fluid balance, says the nutritional therapist Zoë Hill. We lose electrolytes when we sweat, and while water is generally enough to replenish them, if you're working out for longer than an hour, or you're in an especially humid country, they can help to amp up your hydration.
We rate Wellthy by Boots's Daily Hydration+ Electrolyte Powder in Smooth Blueberry (£7 for 12 sachets) and Humantra’s Berry Pomegranate Electrolyte Powder (£19 for 15 sachets). That said, we’re patiently waiting for Kylie Jenner’s K20 electrolytes to hit UK shores – they combine collagen and hyaluronic acid with electrolytes for a beauty as well as a hydration hit.
Echo Flask Hydrogen Water Bottle, £299
For people serious about their hydration, this high-tech bottle infuses your water with molecular hydrogen, a potent antioxidant which is shown to help combat oxidative stress, support recovery and promote long-term vitality. Echo’s bottle pairs with an app to track both your hydration and hydrogen intake, so you can align your water consumption with your activity levels.
Air Up bottles, from £24.99
If finding water boring is standing in the way of increasing your intake, try Air Up. It's a water bottle with fitted pods that flavour your water through scent, rather than adding squash. The scented air is inhaled while you drink, which the brain interprets as taste, allowing flavour without sugar or additives. The pods cost £5.99 for three, and each pod flavours at least five litres of water.
