Best Electrolyte Drinks for UK Runners in Summer Heat
"It's not that hot here" is the most common reason UK runners give for skipping electrolytes — and it's also the most common reason UK runners end up cramping on a warm, humid long run. Temperature isn't the only variable that matters: humidity and effort duration both drive sweat loss just as much, and the UK gets plenty of both during a typical summer marathon or half marathon training block, particularly on the still, muggy days that don't feel dramatically hot but leave you drenched by the end of a run.
Why UK humidity catches runners out
A 22°C day with high humidity can produce a heavier sweat rate than a drier 28°C day, simply because sweat evaporates less efficiently in humid air — which means your body has to produce more of it to achieve the same cooling effect. This is exactly the kind of weather the UK produces regularly in June, July and August, and it's easy to underestimate because the temperature reading alone doesn't tell the full story.
How much fluid do you actually need?
As a baseline, NHS guidance on water, drinks and hydration suggests most people aim for 6–8 cups or glasses of fluid a day — but that's a general population guideline, not a training one. Once you're out running for an hour or more, especially in warm or humid conditions, you're losing sodium, potassium and magnesium through sweat on top of that baseline, and water alone doesn't replace them. Sweat isn't just water leaving your body — it's a genuinely salty fluid, which is why relying purely on plain water during a long, hot session can actually dilute your remaining electrolyte concentration rather than fixing the problem.
Signs you're under-fuelling electrolytes, not just under-hydrating
Cramping late in a long run, unexplained fatigue despite drinking plenty of water, headaches after a long session, and dizziness on standing after a run are all classic signs of electrolyte depletion rather than simple dehydration — and they're often missed because the instinctive fix (drinking more plain water) doesn't actually solve the problem, and can occasionally make cramping worse in genuinely extreme cases.
Why this works better as a daily habit than an occasional fix
It's tempting to think of electrolytes as something you only reach for on the hottest, longest days — but treating hydration as a daily foundation rather than a conditional fix is a better way to think about it. Sodium, potassium and magnesium losses happen every time you train, not just on the sessions that feel obviously sweaty, and topping them up consistently means you're never running a quiet deficit into a big session without realising it. This is exactly why RunnerVits built Daily Hydrate & Perform as a daily formula rather than a "long run only" product: creatine specifically needs a consistent daily dose to keep muscle stores topped up (see our separate guide on creatine for runners), and L-Glutamine's recovery and gut-health benefits are cumulative across a training block rather than tied to any single session. Taking the electrolyte blend alongside these daily, rather than saving it for race day, means all three ingredients are working together the way they're designed to.
The benefit of a single blended daily formula
Buying electrolytes, creatine and L-Glutamine as three separate products means three separate labels to check, three separate scoops to measure, and three separate habits to build and remember every morning — which is exactly the kind of friction that causes a good routine to quietly fall apart after a few weeks. A single blended morning drink solves that by combining all three into one mix, taken once, rather than needing the discipline (and the cupboard space) to manage three different tubs. It also means the dosing across all three ingredients is already worked out and balanced for a runner's needs, rather than something you have to figure out yourself.
What a well-built electrolyte formula should contain
Sodium is the headline mineral — it's lost in the largest quantity through sweat and plays the biggest role in fluid balance — but potassium and magnesium both matter too, particularly for muscle function and cramp prevention. RunnerVits' Daily Hydrate & Perform combines 500mg sodium with potassium and magnesium, alongside 5g creatine monohydrate and 5g L-glutamine, as a single daily formula built specifically around a runner's hydration, performance and recovery needs — not a generic sports drink repurposed for endurance, with a natural citrus flavour rather than an overly sweet gym-drink taste.
Quick answers
Can I just add salt to my water instead?
You can, but getting the sodium-to-potassium-to-magnesium ratio right by hand is fiddly and easy to get wrong, and plain salt doesn't address potassium or magnesium loss, or give you creatine and L-glutamine, at all — a single blended formula removes the guesswork and the extra products.
Do I still need it on easy, low-mileage days?
Yes — because the formula is also delivering a daily maintenance dose of creatine and L-glutamine, taking it every morning regardless of that day's session keeps both ingredients topped up consistently, which is a different logic to an electrolyte-only product you might genuinely reserve for hot or long runs.