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If you don't add electrolytes to your water, you're not going to be hydrating at all
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Let's talk about that. How's it going, guys? My name is Richie Kerwin. I'm a registered nutritionist, researcher
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and university lecturer in nutrition and exercise physiology. Electrolyte products used to be something endurance athletes reached for during long, hot races. Now
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they're marketed for pretty much anyone who drinks water, often alongside the claim that
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water alone doesn't properly hydrate you. So in this video, we're going to break down what
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electrolytes actually are, what happens to them when you sweat, whether you genuinely need to
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supplement them, and who actually stands to benefit. So a few years ago, electrolytes were
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pretty niche. Some marathon runners had them, maybe the odd footballer training in the height
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of the summer. Now, you can't walk into a gym or open Instagram without somebody trying to convince
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you that your tap water is basically useless without a sachet of salt and minerals dissolved
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in it. The pitch usually goes something like this. Water alone can't properly hydrate you
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You need electrolytes to actually absorb it and if you're not adding them you're walking around
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dehydrating without realizing it. That's a pretty strong claim which raises a few obvious questions
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Do you actually need them? Is plain water really not good enough? And if electrolytes do matter
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Who actually needs to worry about them? And who's just paying a premium for flavored salty water
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To answer that, we need to start with the basics. What electrolytes actually are and what they're doing in your body in the first place
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So despite what energy drink adverts might have you believe, electrolytes aren't some exotic performance ingredient
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An electrolyte is just a mineral that carries an electrical charge when it's dissolved in fluid
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like the fluid in your blood or your sweat, or inside and outside every cell in your body
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The main ones you need to know about are sodium, potassium, calcium, magnesium, and chloride
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And the great thing to know is that if you have a semi-decent diet, you already get plenty of them
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from the food you eat. So these minerals do a few really important jobs in your body. First
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they control fluid balance. Water tends to follow sodium around your body. So wherever sodium
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concentration is higher, water tends to follow it, which is how your body keeps fluid properly
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distributed between your blood vessels and the rest of your tissues, rather than it all pooling
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in one place or another Second electrolytes are essential for nerve signaling Every time a nerve fires it because sodium and potassium are rushing in and out of the cell in a very specific
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pattern, creating the electrical signal that travels down the nerve. No sodium or potassium
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movement, no nerve signal. And no nerve signal to your muscles means no movement. Third, they're a
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central part of muscle contraction. The release of calcium ions is the trigger that allows your
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muscle fibers to actually contract in the first place. And like I just said, sodium and potassium
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are what allow the nerve signal to even reach the muscle and tell it to contract. So electrolytes
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are genuinely fundamental to how your body works. You wouldn't survive without them. But the real
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question isn't whether they matter, it's whether you're actually running low on them and need more
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and that's a different question entirely. So when you sweat, you're not just losing water. Sweat also
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carries dissolved electrolytes out of your body with it, mainly sodium and chloride, with much
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smaller amounts of potassium, calcium, and magnesium, all along for the ride. Sodium is the big one to
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pay attention to here because it's lost in by far the largest amounts relative to what you've
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actually got stored in your body. Potassium losses through sweat are important too, but they're small
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compared to your total body potassium stores, so they're far less of a practical concern for most
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people. Now here's the part that really matters for this video. How much sodium you lose in your
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sweat isn't fixed. It varies hugely from person to person and even varies in the same person
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depending on things like heat acclimatization, fitness level and how hard you're training
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Some people are what's called salty sweaters. I know it sounds like a very technical term right
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And they lose far more sodium per litre of sweat than others doing the exact same training
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So because of all the different factors at play, there's no fixed piece of advice on electrolytes that applies to everyone
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And that's a really important point to hold on to because it means a blanket everyone needs electrolytes message
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or a blanket nobody needs them message are both going to be wrong for somebody
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So now that we know this, let's answer this question. Is it true that water alone can't properly hydrate you
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For the vast majority of people doing the vast majority of training sessions, no, that's
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not true. Your body is extremely good at absorbing plain old water You don need to add anything to it for that basic process to work If you doing a normal gym session or playing a bit of five a side or a 10k run in a reasonable temperature
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plain water will hydrate you just fine. Where it gets a bit more complicated is during longer, continuous exercise, especially in the heat
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There's some decent evidence that drinks containing a small amount of carbohydrate and electrolyte
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at a lower concentration than your blood. which are called hypotonic drinks, can help your body hold onto that fluid slightly better
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than plain water during sustained exercise, lasting a couple of hours or more. Now to be clear
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we're not talking about a huge difference, but it does have an effect. Hence the massive market
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for carbohydrate and electrolyte drinks for people doing endurance events like marathons
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So the honest answer is the blanket marketing claim that you can't hydrate with water alone
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is absolutely bullshit for almost everybody watching this in their day-to-day life
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But there is a genuine, much narrower case where electrolyte-containing drinks have a small edge
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over water. And it's really only relevant when you're exercising for a long stretch of time
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or in high temperatures. So not for your average gym session. Now, there's something really
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important that electrolyte marketing tends to skip over entirely. Before you've added a single
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electrolyte tablet to your water bottle. The average person in the UK is already eating more
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sodium than they actually need. The UK government's own dietary survey found that adults are consuming
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around 8.6 grams of salt a day, well above the 6 gram daily maximum that's actually recommended
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And that's not from people standing over their food with a salt shaker. Most of it is already
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baked into breads or in cereals, sauces, ready-made meals and processed foods before it even reaches
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your plate. That matters because excess salt intake isn't a neutral, more is fine kind of
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situation. There's strong evidence that cutting back on salt lowers blood pressure and high blood
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pressure is one of the biggest risk factors for cardiovascular disease there is. So when an
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electrolyte product is marketed at someone who trains for 45 minutes in an air-conditioned gym
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and then goes home to a normal UK diet, you're essentially offering more salt to someone who's
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already over their recommended intake before breakfast. Yes, sodium is essential, but you can
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definitely get too much of it So the idea that the general population is walking around electrolyte deficient and needs to supplement their way out of it is just spin
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So if the average person in a normal gym doesn't need electrolytes, who actually does
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The clearest case is anyone training in genuine heat, especially for longer than an hour
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Think outdoor summer training, football in the sun, or anyone doing endurance events like marathons, triathlons, or long cycling sessions
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Sweat losses in these situations might outpace what a normal diet replaces, and that's when an
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electrolyte drink could help. That said, if you currently train in conditions like that and just
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drink plain old water and still feel like you're performing well, then you probably don't need them
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at all. The other group that might need them is salty sweaters. People who lose unusually high
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amounts of sodium when they sweat compared to everyone else doing the exact same session. You
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might actually notice this as visible white salt stains on dark training kit after a hard session
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If that's you and you're training for long durations or multiple times a day, an electrolyte
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supplement might genuinely be worth trying out in your routine. Now before I finish up, I want to
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mention one more electrolyte claim head on, that electrolytes stop muscle cramps. You'll hear this
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constantly and on the surface it makes sense. Sweat takes electrolytes with it. Electrolytes are
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needed for muscles to contract properly, so low electrolytes must cause cramp, right? Here's the
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problem. When researchers have actually gone looking for the link directly by measuring blood
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electrolyte levels in athletes who cramp versus those who don't at the same event, they consistently
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haven't found a meaningful difference between the two groups. The leading theory now points more
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towards local muscle fatigue and altered nerve signaling at the muscle itself rather than a
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simple electrolyte shortage. So if you're a salty sweater doing long sessions, topping up electrolytes
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might help as part of the picture. But for most people, cramp might not be solved by a sachet of
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electrolytes, but it won't hurt to try some to see if there's an improvement. Just don't hold your
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breath. So where does that leave us? If you're doing a normal gym session, a five-a-side footy
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game, or anything under about an hour in reasonable temperatures, plain old tap water has you covered
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If you're training hard in the heat for longer than that, sweating heavily, or you know you're
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a salty sweater, well, that's when an electrolyte potentially could be useful. Everyone else is just
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paying for flavored salty water. As always, if you have any questions, let me know in the comments
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below and remember to like and subscribe to the MyProtein YouTube channel for more great
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evidence-based nutrition information
