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 look for in the best electrolytes for Hyrox? 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, and sodium is the one you lose in big enough amounts to affect performance. The American College of Sports Medicine's position stand on exercise and fluid replacement says the same: 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). A tablet with 200mg won't cover a 1,200mg loss. That's your first filter: check the sodium per serving on the back of the pack and ignore the claims on the front.
A useful starting point for a Hyrox effort is 300-700mg of sodium per serving, more if you're a salty sweater or racing in the heat. White marks on your kit after a hard session are a rough sign you're at the higher end.
The other minerals matter, but less
Potassium, magnesium and calcium all play a part in muscle contraction and fluid balance, and they belong in a good formula. You lose small amounts of them in a single session, though, so huge doses of them mostly serve the label.
Treat them as the supporting cast. A good electrolyte covers them at sensible levels and puts its real weight behind sodium. If a product shouts about ten minerals and hides the sodium figure, that tells you where its priorities are.
Format decides whether you actually take it
The best formula is the one you use every time. 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 is one more thing to get wrong.
Ready-to-drink and pre-measured options take that hassle away. You skip the scooping and guessing, and there's no clumpy powder at the bottom of the bottle. In a sport with tight margins and a chaotic race morning, that's worth more than a slightly cheaper tub you forget to pack.
Cost per serving is the fair way to compare. A £30 tub that lasts 15 sessions costs more per use than it looks. Work out what one serving costs before you decide something is good value.
How to use them around a Hyrox
Start topped up. Have an electrolyte drink in the hour or two before you race so you're ahead from the start. In longer training blocks or hot sessions, sip steadily. Afterwards, replace what you lost as part of your normal recovery.
Keep the during-race plan simple for a standard Hyrox. Most athletes finish in 60-90 minutes, so the bigger wins come from turning up hydrated and replacing properly afterwards. For the full walk-through, our Hyrox hydration strategy covers before, during and after, and our electrolyte tracking guide helps you work out your own losses.
Where Interval fits
We built Electrolyte+ for exactly this. A box of 20 sticks is £19.99, which works out at about £1 a serving. Each stick gives you 1500mg of electrolytes plus 500mg lion's mane and 500mg maca, and it's 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 reach for at 5am. That matters far more than the brand on the label.
Signs you're getting it wrong
Your body tells you. Cramping late in a session or race, a pounding headache afterwards, or feeling flat and heavy-legged while drinking plenty of water all point to low sodium. Plain water on its own can make it worse, because it dilutes the sodium you have left.
On the flip side, a salty crust on your face and kit, stinging eyes from sweat and a strong craving for salty food after training suggest you lose a lot of sodium and need the higher end of the range. Use these signs to adjust. 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, starting topped up and replacing afterwards covers it, because a standard Hyrox finishes in 60-90 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.
Can I just add salt to water? You can, and it's cheap. It's hard to get the dose right and it tastes rough, though. A measured formula is easier to use every time, and that's what counts.
Pick the electrolyte that covers your sodium loss, supports the rest at sensible levels and survives a hectic race morning. That's the one that holds your pace when the wall balls start.