Mixing an electrolyte drink had become a firm part of my morning routine. The moment I was downstairs, I’d be reaching for a snazzily branded sachet. It didn’t matter what workout I had planned – I’d always find an excuse to accessorise my water. I must have tried every brand and flavour on the market, easily attracted by slick packaging and a novel taste, rarely glancing at the actual ingredients. But then I began to ponder the extra sodium I was consuming, which ranged from 300mg per sachet to a massive 1,000mg hit.
That 1,000mg is a whole gram of pure sodium – which is where the maths gets alarming. Because salt is only about 40% sodium, you have to multiply any sodium figure by 2.5 to find the true salt equivalent. Suddenly, that 1g of sodium becomes 2.5g of salt. Drinking just two of those heavy duty sachets meant I was downing 5g of salt – dangerously close to the NHS daily maximum of 6g, before I’d even eaten a meal. While sodium is the main electrolyte lost in sweat, these numbers made me question my habit. Was this actually supporting my training and health, or was I just heavily salting my water to make it more interesting?
That question led me to look at salt intake more broadly. A recent study by the British Heart Foundation found that the average Brit consumes the equivalent salt found in 155 packets of crisps each week – around 8.4g per day, roughly 40% more than the advised limit. Consuming too much salt carries risks – but more on that later. First, where do electrolytes fit into that picture? Do we really need them day to day, or are they better reserved for very long rides in hot weather?
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What are electrolytes?
For riders tackling the world’s biggest races, carefully managing fluid and sodium losses is critical
(Image credit: Getty Images)
Electrolytes – sodium, potassium, magnesium, and calcium – are essential minerals the body needs to function properly. They play vital roles in maintaining fluid balance, transmitting nerve signals, enabling muscle contractions, and balancing blood pH. When we exercise, the body cools itself by sweating, and because sweat is derived from your blood plasma and extracellular fluid, it contains dissolved minerals – predominantly sodium. But to what extent do we need to replace the electrolytes we sweat out?
As a sports nutritionist for Red Bull-Bora-Hansgrohe, Will Girling works with riders tackling the world’s biggest races, including the Tour de France, where carefully managing fluid and sodium losses over long, hot stages is critical. Failing to replace such losses could cause serious problems. “At its most extreme,” said Girling, “that could include hyponatraemia [low blood sodium levels, below the normal range of around 135-145 mmol/L]. More commonly, you might experience dehydration, headaches, nausea and a reduced ability to exercise.” But what about for recreational cyclists – do we need to take similar precautions?
Electrolytes don’t directly hydrate you, but they help your body retain and use the fluid you drink more effectively. This distinction is widely misunderstood, reckons Dr Lewis James from Loughborough University. “People mistakenly think that by having an electrolyte product, they’re getting better hydration, so they don’t focus on the thing that matters most – fluid intake,” he said. “The electrolyte content won’t magically make them more hydrated, not unless they are also drinking the correct amount of water they need.”
According to the experts, electrolyte use is considered most useful during sustained exercise lasting longer than 60 minutes, in hot environments, or for individuals who consistently lose relatively high amounts of sodium in their sweat, often indicated by signs such as white salt marks on clothing or sweat that stings the eyes.
Electrolytes drive hydration through a process called osmosis. In simple terms, water naturally moves toward areas with a higher concentration of sodium to balance things out. Because water always follows sodium, higher sodium levels essentially prompt the body to ‘hold on’ to more fluid. “Electrolytes assist water absorption and retention, so anything you drink can contribute more readily to the body water pool if electrolytes are present,” explained Professor Stuart Galloway from the University of Stirling.
Much of the time, we replenish electrolytes naturally through the foods we eat day to day: sodium from salt, potassium from bananas and potatoes, and magnesium from nuts, seeds, and leafy greens. During prolonged or very intense exercise, however, particularly in hot conditions, supplementation can offer a convenient way to replace what’s lost through sweat.
What’s inside the sachets?
There’s an array of products on the market
(Image credit: Future)
Brands selling electrolytes are becoming increasingly visible, with the global electrolyte powder market alone expected to exceed $700m (£530m) within the next four years. Ingredient lists vary significantly between brands, but sodium is usually the primary ingredient, alongside potassium, magnesium and calcium. Many products also go beyond basic electrolytes. Some include carbohydrates to provide a quick energy source, while others also contain caffeine, amino acids, or “performance blends” designed to boost alertness or gut health. Flavourings, sweeteners such as stevia or sucralose, and anti-caking agents are also commonly used to improve taste and shelf stability.
The language used to market these products makes big, often vague promises. Some brands position electrolytes as an everyday essential, even those with up to 1,000mg of sodium, claiming benefits such as improved energy, enhanced performance, sharper focus and reduced fatigue. As a result, the lines between evidence-based sports nutrition and more questionable “wellness” fads have become increasingly blurred.
DIY it at home
Want to ditch the expensive sports drinks? Dr Carrie Ruxton’s DIY alternative takes seconds to mix and costs mere pennies.
To make 500ml, mix the following ingredients:
- 150–200ml 100% orange juice
- 300–350ml water
- 1 sachet of oral rehydration salts (like Dioralyte or a generic supermarket brand) for hot weather or sweat- heavy sessions.
- Want an even cheaper fix? Swapping the sachet for a single gram of standard table salt provides about 400mg of sodium for next to nothing.
Do we need them, and if so, when?
Known heavy sweaters may need to take on more
(Image credit: Future)
With electrolyte powders and tablets now regular fixtures in the supermarket, it would be easy to assume they’re an essential part of every rider’s training routine. But for most cyclists, the reality is more nuanced. “There’s salt everywhere in all of our diets,” James said. “Most of us get a lot more than we need on a daily basis, so I would question whether it’s needed for someone who is recreationally active and mainly exercising for health purposes or enjoyment.”
Girling echoed this view, adding that for exercise lasting less than two hours, hydrating beforehand and drinking to thirst during is generally sufficient, unless conditions are very hot or sweat sodium losses are unusually high. In these situations, consuming an electrolyte drink before exercise may help support fluid balance from the outset. “If exercise is prolonged – over two hours – you probably want to be considering it [electrolytes],” Girling added, recommending cyclists also check the sodium content of their gels and carbohydrate drinks.
However, many factors influence electrolyte requirements. Galloway points out that there’s no one-size fits-all approach. “It depends on how long the ride is going to be, what the conditions are like, what else the rider might be eating or drinking during that ride, and individual differences,” he said. The demands of a steady cafe ride in spring are very different from those of a four-hour ride or race at the height of summer. For James, the conversation changes when riders are training at a high level, completing multiple sessions a day, or preparing for events in hot environments. In these situations, sodium losses through sweat may exceed dietary intake, potentially affecting both performance and recovery.
For recreational cyclists, electrolyte supplementation becomes useful during back-to-back training days in hot weather or on longer, more demanding sessions where sweat losses are higher. The estimated average sweat sodium loss is between 800 and 950mg per litre of sweat, although this varies considerably between individuals owing to genetics and heat adaptation, with reported values ranging from around 200mg to 2,000mg per litre. While sweat sodium tests are available at a cost, most sports nutritionists consider them an unnecessary expense for everyday riders. Instead, simple observation is usually enough: riders who notice white marks on their kit after a ride correctly infer that they have lost significant amounts of sodium.
Sodium is the primary electrolyte lost in sweat, so that should be the main focus. James explained that, while other electrolytes (potassium, magnesium, and calcium) are essential for normal bodily function, there is limited evidence that supplementing them during exercise provides additional benefits. The consensus among the experts we consulted was that hydration strategies can be simple and cheap. The body doesn’t distinguish the sodium in table salt from the sodium in a supplement. “One gram of salt contains around 400mg of sodium,” Girling pointed out, suggesting that you don’t necessarily need to spend money on sachets and tablets.
Across the board, the experts suggested that performance generally begins to decline once dehydration exceeds 2% of body weight, meaning mild dehydration during shorter or lower-intensity rides is usually well tolerated by the body. “As you go beyond 2% dehydration, you may begin to experience brain fog, lose concentration, feel greater fatigue and you’ll start to heat up, as you’ve less fluid to keep your temperature down,” said Dr Carrie Ruxton, dietitian and co founder of Salt St Andrews gym.
To estimate your own fluid losses, weigh yourself before and after a ride. As a guide, a 70kg rider who loses 2% of their body weight, or 1.4kg, during a ride will have lost around 1.4 litres of fluid. How quickly you reach this level of dehydration depends on your sweat rate, which varies depending on temperature, intensity, and individual physiology.
Can you have too many electrolytes?
The weather, the length and intensity of your ride are all factors
(Image credit: Future)
Supplementing with electrolytes may be useful for riders covering long distances in very warm weather, but if you’re regularly emptying sachets into your water, can you have too much of a good thing? “It will all come down to salt balance over the day,” James said. “If they’re consuming too much salt, then there could be negative effects.” One of the biggest concerns around electrolyte products is excessive sodium intake. Too much salt over time has been linked to high blood pressure, a major risk factor for cardiovascular disease. For those who already have high blood pressure, Ruxton stressed the importance of monitoring the combined sodium intake from food or supplements.
The experts consulted all agreed that healthy, active individuals are unlikely to run into problems from occasional electrolyte use around training. “Generally, if you’re young and active anyway, with a healthy balanced diet, your body is good at sorting out how much salt and how much other electrolytes it needs,” said Galloway. “We excrete the excess and retain what we need.” More immediate issues tend to come from overuse during exercise. According to Girling, excessively concentrated drinks can contribute to gastrointestinal distress and may even slow carbohydrate absorption, potentially impacting performance. Higher sodium intake can also lead to short-term fluid retention, showing up as slight weight fluctuations or a bloated feeling after use. “That’s only important if you’re doing an activity or racing where it’s important not to gain weight the next day,” Girling said. Ultimately, electrolytes are best viewed as a tool rather than a daily necessity – useful in the right conditions, but otherwise pointless. As Ruxton pointed out, electrolytes should be treated similarly to energy gels – used strategically. “It’s about using these things in a planned way and doing the planning when you’re training,” she said.
Instead of reaching for an electrolyte sachet first thing in the morning, I’ll be taking a more mindful approach. For most of us, especially those training in cooler climates like the UK, electrolyte supplements aren’t a daily necessity. They have their place – particularly during longer rides, in the heat, or when sweat losses are high – but otherwise, most of us are likely to maintain electrolyte balance through our normal diet. Since writing this article, I’ve already kicked my electrolyte habit, and instead I’m paying closer attention to the amount of salt in my diet, which thankfully appears to be relatively low. For now, the sachets will stay in the cupboard – until I really need them.
How much should we aim to consume?
White marks left on clothing may be a sign you’re a salty sweater
(Image credit: Lisa Charlebois)
Lisa Charlebois spoke to a range of experts in search of a baseline intake suggestion.
Dr. Cristhian Montenegro – PhD in human bioenergetics, with a focus on cardiovascular and muscle physiology – argues the baseline sodium question is more nuanced than nutrition labels suggest.
“Sodium for cyclists during exercise is tied to the amount of water they are looking to retain or replace,” he says. “Sodium and carbohydrates like glucose and sucrose all help with the retention of water, so the amount of sodium supplementation will not only depend on water intake but also the total other water-retaining sugars in drink mix or gels. In short, up to 500mg is a good baseline range if you’re drinking one 500ml bottle per hour.
“Generally, 500 to 1,000mg of sodium per hour is justified for performance-oriented hard efforts, as long as it is ingested correctly and for the right reasons, essentially with water, for water replenishment,” he says. “If it is hot and an athlete is working hard and generating metabolic heat, total sodium consumption may be even higher.”
However, he draws a sharp line between the elite athletes and the everyday rider. “As with most things marketed using professional athletes, us ‘mere mortals’ will get by with much less, especially on moderate intensity rides.”
Andrea Rumschlag, a Registered and Licensed Dietitian, cites the general guideline of 300 to 600mg per hour. “I always like to remind athletes (or any consumer for that matter) to consider who is selling you something,” she says. “Higher levels of sodium are typically needed for moderately intense activity exceeding two to eight or more hours. Otherwise, the average sweater doing one to two hours may be just fine with a sports drink, water, and a salty snack post-ride.”
Frank Overton, founder of FasCat Coaching, with a Masters in Physiology and a USA Cycling Level 1 accreditation, puts it plainly: “Sodium loss varies wildly between people, roughly anywhere from 100 to 2,000mg per hour. That’s why a one-size-fits-all 1,000mg product is ideal for some riders and overkill for others. The answer is genuinely individual.”
The general consensus was that, for rides under two hours in cool conditions, water and food will work well. Rides from two to four hours, electrolytes in the 300 to 500mg range are reasonable. For rides over four hours, in heat, or for known heavy sweaters, higher sodium supplementation may be genuinely beneficial.
Sweat tests are available for those who really want to know if they’re losing more or less sodium than the average rider through sweat. Lindsey Hunt, MSc, PhD and Senior Sports Scientist at Precision Hydration, which offers the testing and tailored electrolyte drinks, told us: “Sweat rate you can train and measure. But how much sodium you lose in that sweat is largely down to your genes, and it barely shifts with fitness or acclimatisation. We see people losing anywhere from around 200mg of sodium per litre of sweat to over 2,000mg — that’s a tenfold difference between two riders who look identical on paper. So if you’re a salty sweater doing long, hot rides, generic advice can leave you a long way short without you ever knowing why.”
