Why science is warning against drinking electrolytes every day

For many, an electrolyte drink has become a daily staple. On social media, wellness influencers constantly post about their favourite brands and flavours – and it’s starting to feel as though electrolytes are a health need rather than a want.

However, NHS Doctor and marathon runner Dr Miranda Layton – also known as Dr Mimi Runs – has warned her followers about the potential risks of drinking too many electrolytes.

In a recent reel on Instagram, Dr Mimi, who regularly posts sports science content, shared a warning: ‘Here is what the fitness industry doesn’t want you to know: You might be drinking too many electrolytes. Most electrolyte drinks are high in sodium, which is just salt – the same stuff that we put on our food. Most people already get enough salt in their diet without factoring in all the salty electrolyte drinks. We know that too much salt in the blood over time can raise your blood pressure, but in the short term, overconsumption of electrolytes can cause dangerous changes to your heart rhythm – especially if you’re not actually dehydrated.’

This isn’t to say that all electrolytes are unnecessary. When you’re exercising, often for long periods, your body’s fluid balance can be affected, which can, in turn, impact your performance. ‘Electrolytes are charged minerals like sodium, potassium and magnesium that help your body to absorb fluids, contract muscles, transmit nerve signals and regulate pH levels,’ says Sanjeev Pathak, a longevity expert and host of the Let’s Grow Young podcast. ‘They’re vital – but they’re also easy to lose.’

As Pathak adds, ‘while a balanced diet, lightly salted meals and drinking to thirst work for many, certain situations demand more intentional hydration’. He says to consider an electrolyte drink – ideally in powder form, without gelling agents or fillers – in the following scenarios.

Exercising in the heat

Pathak says that you can lose up to 7g of sodium per day through sweat. ‘Rehydrate with salty water to thirst to prevent dehydration and exercise-associated hyponatremia (low blood sodium).’

Cold or high-altitude training

‘Both can disrupt your thirst response, which means that you may under-drink without realising it,’ notes Pathak. ‘Proactive fluid intake becomes critical.’

Low-carb or keto dieting

‘Low insulin levels on these diets trigger sodium loss through urination,’ says Pathak. ‘Combine this with naturally low-sodium whole foods and you’re at risk of sodium deficiency. Translation: low carbers need more salt.’

In a 2015 study investigating the effectiveness of salt supplementation during a Half Ironman triathlon, researchers found that athletes who supplemented with salt, plus other electrolytes and a sports drink, before and during the race, improved their race times by an average of 8%. The researchers also found that the salt supplementation helped to stimulate thirst, which meant that the athletes drank more and improved their hydration.

There’s also evidence to suggest that electrolyte supplementation can support exercise recovery. A recent study published in the Journal of Sports Science and Physical Education investigated the impact of different pre-exercise hydration strategies for HIIT (high-intensity training), including water, electrolyte solutions and carbohydrate-electrolyte sports drinks. The randomised control trial of 60 athletes (30 men and 30 women, aged between 18 and 35) found that those who consumed carbohydrate-electrolyte sports drinks demonstrated significantly better performance and recovery outcomes than those who consumed water or electrolyte solutions alone.

As with most aspects of nutrition, when it comes to electrolytes, balance is key. ‘Excess can be just as harmful as deficiency,’ says Pathak. ‘Overdoing it can lead to arrhythmias, nerve dysfunction and organ damage. Balance is key. I recommend only supplementing with electrolytes when your body’s losing more than food can replace.’

Here, Pathak notes the most common electrolyte overloads and their symptoms.

• Sodium (hypernatremia): Thirst, confusion and seizures.
• Potassium (hyperkalemia): Irregular heartbeat, weakness and risk of cardiac arrest.
• Calcium (hypercalcemia): Fatigue, kidney stones and confusion.
• Magnesium (hypermagnesemia): Nausea, low blood pressure and breathing issues.
• Chloride (hyperchloremia): Weakness and high blood pressure.

Dr Ravina Bhanot is an NHS GP, specialising in women’s health. Explaining the shorter-term risks of excessive electrolyte consumption, she says: ‘High sodium can cause bloating, increase thirst and drive up your blood pressure and put pressure on your heart, which is not good for your heart health – and some high electrolyte drinks can cause stomach upset and irritate the gut lining which can affect your bowel habit.’ Too much magnesium in drinks can also cause diarrhoea, she adds.

There are longer-term risks as well. ‘An imbalance of electrolytes in the body, like high sodium or high potassium, can be very dangerous and affect the nervous system or lead to heart arrhythmias and palpitations,’ says Bhanot. If your potassium or sodium levels are too high, she says that you can also risk acute kidney injury. Plus, increased blood pressure can increase your risk of heart disease.

While you might require more electrolytes if you sweat more, Bhanot says that other things also come into play. It will depend on how hot it is and the humidity levels, as well as the duration and intensity of the exercise that you’re doing. For instance, if you’re training for a marathon over the summer months, you’ll probably want to take on electrolytes for your long runs and harder sessions.

Generally, experts – including Dr Mimi – advise electrolyte drinks in certain contexts and conditions. As she summarised in the Instagram post: ‘Unless you’re really exercising for more than 75 minutes, exercising in heat or altitude, you probably don’t need the extra salt from the electrolytes.’