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Do You Really Need Electrolyte Supplements for Better Hydration?

Electrolytes, salts and minerals that can be found in our blood, are essential to our survival; they help us balance our body fluids and enable muscles and nerves to work correctly. (They do so via tiny pulses of electrical current, hence their name.) Today they are also sold in hydration aids such as sachets, tablets or gels, containing sodium, which is essential for fluid balance, and often potassium, magnesium or chloride, which help keep our muscles, nerves and blood pressure healthy.

Modern life may make us less inclined to need them

"Maintaining electrolyte balance is vital for many physiological processes," says Bethan Crouse, performance nutritionist at Loughborough University. "It's essential that we are intaking enough across a day." She says that supplements are particularly useful for "exercisers who train or compete for particularly long periods of time, for example for triathlons, Ironman or marathons, or are exercising in hot conditions", since they are more likely to sweat electrolytes out more. A supplement "can help replace electrolytes lost in sweat, and also increase fluid retention so that our body holds onto more fluid overall". Their hydrating qualities are also useful to those with diarrhoea, kidney disease or who struggle with hydration in general.

Even if you're not doing a marathon, they can help, says Nonni's in-house nutritionist Diana Bell-Irving. "Today's habits - long hours at screens, travel, caffeine, alcohol, saunas, exercise, stress or even air-conditioned offices - all increase dehydration risk." Electrolytes can in fact be found in all sorts of food (see below), but it's not a given we're eating it, she argues, making a supplement particularly handy. "According to national data, only around 17 per cent of British adults meet the recommended threshold for a balanced diet."

The flavour and fizz can also make them a more appealing way of hydrating, says Stuart Galloway, professor of exercise physiology at the University of Stirling. "If it makes you drink a bit more and it helps you stay hydrated, then that's a good thing."

BetterYou Magnesium Water, £17.99 for 12 x 250ml. *BUY*

FourFive+ Hydro tablets, £8 for 20 tablets. *BUY*

Sixways Daily Hydration Electrolyte Formula, £30 for 30 servings. *BUY*

Nonni Sicilian Lemony Lemon cans, £3.20 each. *BUY*

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"Day to day, just from the food you eat, you'll be getting enough electrolytes," says Galloway. "Most people who eat a healthy balanced diet with optimal fluids - ie, water - will not need electrolyte supplements," confirms Professor Alexandra Johnstone of the University of Aberdeen. "Our body is very good at keeping electrolytes within the correct amounts."

She points out that magnesium can also be found in "nuts, seeds, whole grains, dark chocolate, leafy greens", while Crouse says that "pretzels, white bread, salted nuts and beef jerky are particularly high in sodium. Incorporating some of these as a post-exercise snack could be really useful." Others, meanwhile, advocate just a few slices of cucumber in water.

You can also take too much. "Over-supplementation, particularly with sodium, can contribute to blood pressure and bloating," says Bell-Irving. "Excess potassium and magnesium can also disturb heart rhythm or digestion."

"We do see them being overused in low-to-moderate intensity exercise," warns Crouse. "If you're doing, say, 30 minutes to an hour in the gym, then you probably don't need to worry about them," says Galloway. He also thinks that modern life may make us less inclined to need them, not more. "Our foods are probably higher in salt than they were before, and our behaviour is more sedentary because we're sat at computers for a lot of our working day. So actually, our water losses are lower, and our salt intake is probably higher."

Whether you need electrolyte supplements or not also depends on how much of a "salty sweater" you are. You could get tests done, or you could simply observe or taste your own sweat, says Galloway, and note how much salt you are losing. If you are not in drastic need, but just want to make sure you stay on top of your hydration, "look for lower-salt formulations where the sodium sits closer to under 100mg per 330ml", says Bell-Irving. (A typical sports drink might contain 160mg for roughly the same volume, while "functional hydration powders often deliver 200-500mg of sodium per serving".)

Regardless: "The key to hydration is still, essentially, water," says Galloway.