Best electrolytes for Hyrox: what to look for
Hyrox punishes the under-fuelled. An hour of running broken up by sleds, burpees, and wall balls means a lot of sweat, and most of what you lose in that sweat is sodium. Get your electrolytes right and you hold pace through the back half. Get them wrong and you fade, cramp, or spend the last station fighting your own legs.
So what should you actually look for in the best electrolytes for Hyrox? Three things: a sodium dose that replaces what you lose, sensible support minerals, and a format you'll actually use on race morning. The flashiest tub rarely scores well on any of them.
Sodium is the one that counts
Sweat is mostly water and sodium. You lose smaller amounts of potassium, magnesium, and calcium, but sodium is the electrolyte you lose in quantities big enough to affect performance. The American College of Sports Medicine's position stand on exercise and fluid replacement makes the same point: sodium is the priority for athletes sweating hard for over an hour (Sawka et al., 2007).
Sweat sodium varies a lot between people. Some athletes lose around 400mg per litre, others lose over 1,500mg (Baker, 2017). You can't fix a 1,200mg loss with a tablet that gives you 200mg. That's the first filter: check the sodium per serving, not the marketing on the front.
A useful starting point for a Hyrox effort is something in the 300 to 700mg sodium range per serving, scaled up if you're a salty sweater or racing in heat. The white residue on your kit after a hard session is a rough clue you're on the higher end.
The other minerals matter, but less
Potassium, magnesium, and calcium all have a role in muscle contraction and fluid balance. They belong in a good formula. But the doses you lose in a single session are small, and cramming a tub with huge amounts of them is usually about the label, not your legs.
Treat them as supporting cast. A solid electrolyte covers them at sensible levels and puts its real weight behind sodium. If a product brags about ten minerals and buries the sodium content, that tells you where its priorities sit.
Format decides whether you actually take it
The best formula is the one you use consistently. On a normal training day that's easy. On race morning, when you're nervous and rushing, mixing a scoop and finding a clean bottle becomes one more thing to get wrong.
Ready-to-drink and pre-measured options remove that friction. No scooping, no guessing, no clumpy powder at the bottom of the bottle. For a sport where the margins are tight and the morning is chaotic, that consistency is worth more than a slightly cheaper tub you'll forget to pack.
Cost per serving is the honest way to compare. A £30 tub that lasts 15 sessions costs more per use than it looks. Work out what one serving actually costs before you decide something is good value.
How to use them around a Hyrox
Start topped up. Drink an electrolyte serving with water in the hour or two before you race, so you're not playing catch-up from the gun. During longer training blocks or hot sessions, sip rather than chug. After, replace what you lost alongside your normal recovery routine.
Don't overthink the during-race piece for a standard Hyrox. Most athletes finish inside 60 to 90 minutes, so the bigger wins come from arriving hydrated and replacing properly afterward. For a full walk-through, our Hyrox hydration strategy covers the before, during, and after in detail, and our electrolyte tracking guide helps you work out your own losses.
Where Interval fits
We built Electrolyte+ for exactly this use case. It's a 20-pack at £19.99, which works out at £1 per serving, so the maths is easy to defend. It's a calcium-rich formula that also includes Lion's Mane and Maca, and it comes pre-measured so race morning is one less decision.
Check your own sodium needs against whatever you choose, ours included. Match the dose to your sweat and pick a format you'll actually reach for at 5am. That matters far more than which brand sits on the label.
Signs you're getting it wrong
Your body gives you feedback. Cramping late in a session or race, a thumping headache afterward, or feeling flat and heavy-legged despite drinking plenty of water all point to under-replaced sodium. Plain water on its own can even make it worse, because you dilute what sodium you have left.
On the other side, a salty crust on your face and kit, stinging eyes from sweat, and a strong craving for salty food after training all suggest you're a heavy sodium loser who needs the higher end of the range. Use these clues to adjust rather than guessing. Heat, humidity, and travel all push your needs up, so a formula that works in a cool gym in January may fall short at a summer race.
Common questions
Do I need electrolytes during a Hyrox, or just before? For most people, arriving topped up and replacing afterward covers it, since a standard Hyrox finishes inside 60 to 90 minutes. If you're slower, racing in heat, or a heavy sweater, a serving partway through helps.
Are electrolyte tablets enough? Only if the sodium dose matches your loss. Many tablets are low in sodium, so check the number per serving rather than assuming a tablet does the job.
Can I just add salt to water? You can, and it's cheap, but it's hard to get the dose right and it tastes rough. A measured formula is easier to use consistently, which is what actually matters.
Pick the electrolyte that covers your sodium loss, supports the rest at sensible levels, and survives contact with a hectic race morning. That's the one that holds your pace when the wall balls start.