Electrolytes can be 'the key' to boosting energy levels in the heat - 6 of the best to try

As the weather heats up, often the first thing to go is hydration, and when our levels of electrolytes fall, symptoms can include nausea, headaches, and lethargy. Hardly the recipe for a good time in the sunshine.

One of the ways to keep electrolytes topped up is via supplements. These have become a must-have among fitness fans, early risers, and travellers, as well as those looking to beat the heat, with some airlines now stocking them on board, as we lose up to 1.6 litres of water on a flight.

But what are electrolyte supplements all about? Here, woman&home speaks to a nutritional research specialist and a nutritionist to reveal what electrolytes do, the best ones to try, and what to know before buying, whether you're looking for solutions to sleep in the heat, recover quicker from exercise, or just thrive through the summer and avoid the signs of dehydration.

What are electrolytes?

Simply put, electrolytes are salts, minerals, and other substances that help regulate the fluid balance in our bodies. They include sodium, potassium, chloride, magnesium, calcium, phosphate, and bicarbonates.

These are present in the body's cells and fluids like blood and urine, so maintaining a good level of electrolytes is key for most bodily and brain functions.

"They regulate hydration, nerve function, and muscle contractions - all essential for physical and mental performance," explains Dr Harry Jarrett, a nutritional research specialist and the head of science and research at Heights.

What do electrolytes do?

Electrolytes help to maintain proper hydration levels, keeping our muscles and nerves working properly. In turn, this keeps our energy levels up, brains focused, and bodies working as well as they can. In hot weather, this is particularly essential.

"Key minerals like magnesium, potassium, and sodium help balance the fluids inside and outside our cells, ensuring optimal cell function and energy production," says Dr Jarrett.

"That’s why proper hydration isn’t just about drinking more water. It’s also about replenishing the electrolytes our bodies need to stay energised and alert."

What happens when your body is low on electrolytes?

Some of the more common signs your electrolyte levels are low include: feeling weak, cramping muscles, headaches, irregular heartbeat, confusion, and nausea.

You'll also likely feel tired and lethargic due to dehydration, the experts say.

If it's hot outside, if you regularly and intensely exercise (more than 1 hour at a time), spend time travelling, or are under the weather, you're more likely to have lower electrolyte levels.

Benefits of electrolytes

1. Improved muscle function

Whether you do dedicated treadmill workouts or simple exercises for longevity, electrolytes can help boost performance and motivation levels, as they have a direct impact on the muscles and nerves in the body.

"Sodium, potassium, magnesium, and calcium work together to both trigger and relax our muscle fibres - without them, our muscles wouldn’t work properly," says Wilkinson. "Optimum electrolyte levels can therefore reduce the risk of muscle cramps, improve our muscular endurance, and support faster recovery after exercise."

2. Reduce tiredness

One of the hidden warning signs of dehydration is tiredness, and electrolytes can help restore hydration overnight, reducing tiredness in the morning, boosting energy levels, and improving sleep.

"Water is fundamental to nearly every physiological process in the body, particularly those related to energy production and brain function," says Dr Jarrett. "When the body loses more water than it takes in, blood volume decreases, making the heart work harder to pump oxygen and nutrients through the bloodstream to the muscles and organs. This extra strain can cause physical and mental fatigue."

3. Boosts concentration

If dehydration makes you tired, it's only natural that it also makes it harder to concentrate. "Dehydration affects the brain's ability to function efficiently," says Dr Jarrett.

"Even mild dehydration can reduce concentration, impair mood, and slow down cognitive processes, which contributes to feelings of mental exhaustion or ‘brain fog’."

This is why staying properly hydrated is key, he says, for daily functioning and as a way to improve your brain health. "Water supports cellular function and helps keep our systems running smoothly."

4. Helps maintain healthy blood pressure

Electrolytes like sodium and potassium work together to control how much fluid is in the body and how wide (or narrow) your blood vessels are, says Shona Wilkinson, a certified nutritionist, supplement specialist, and lead nutritionist at Dr.Vegan.

"Keeping these minerals in balance helps maintain steady blood pressure and reduces strain on your heart and blood vessels, supporting overall cardiovascular health," she says.

5. Boosts general wellbeing

Electrolytes also play a key role in the body's pH levels. The body's pH is essential to many of life's processes, including oxygen delivery, protein structure, and various other biochemical reactions.

These minerals "help keep our blood’s pH within a very narrow and healthy range of about 7.35 to 7.45," says Wilkinson. "They do this through ions like bicarbonate, which act as natural buffers to neutralise excess acids. This balance is essential because even small changes in pH can affect how your cells function, and keeping it stable ensures our body’s systems work at their best."

Best electrolytes

Tips for buying electrolytes

• Check for sweeteners: "Sweeteners can impact the gut microbiome, which plays an enormous role in our day-to-day health," warns Wilkinson, so try to keep these to a minimum.
• Aim for variety: "It’s also worth choosing a product that contains a variety of electrolytes, such as sodium, potassium, magnesium, and chloride, rather than choosing one that contains just one of these," she adds.
• Explore flavours: With so many electrolyte brands to choose from these days, have a browse before buying. Some (like these from Hi5) are completely neutral in taste, whereas most others come in a variety of fruit-based flavours.
• Weigh up tablet vs powder: Both have their advantages. Tablets and powder in sachets are easier to travel with than powder in a tub, but they will be more expensive.
• Look into multipack options: You'll find that many brands offer electrolytes in multipack options. These may be cheaper to buy in the long term than single tubes or packets.

Do you need electrolyte supplements?

Like all supplements, you don't need electrolytes in powder or tablet form to get enough of them in your diet. They should be contributions to a regular diet, not replacements.

Electrolytes are naturally found in foods like:

• Sea salt
• Pickles
• Broth
• Bananas
• Sweet potatoes
• Spinach
• Beans
• Nuts and seeds
• Leafy greens
• Dairy products
• Fortified plank milks
• Coconut water

That being said, it can be challenging to get enough electrolytes from diet alone - especially during hot weather or if you regularly exercise.

"For this reason, supplementation can be a reliable way of maintaining optimal balance, ensuring your body has the minerals it needs to stay hydrated, support muscle function, and keep your system working at its best," says Wilkinson.