How to hydrate for boxing and MMA training.
Fighters lose more sweat than almost anyone and water alone does not replace it. Sodium numbers, how to work out your sweat rate, and a before-during-after routine that stops round-three cramp.
Fighters lose more sweat than almost any other athlete: a hot gym, layers of kit, and 90 minutes of rounds can cost one to two litres an hour. Water alone does not replace what you lose, because sweat is salty. The fix is to start the session already topped up with sodium, potassium and magnesium, keep sipping through it, and replace what you lost afterwards. Here is the practical version, with numbers.
- You lose 500 to 1,500mg of sodium per litre of sweat. Water alone dilutes what is left.
- Cramp in round three is almost always sodium and fluid, not fitness.
- Drink 500ml with electrolytes 20 to 30 minutes before, sip 200ml every 15 minutes during, and replace 1.5 times what you lost after.
- Weigh yourself before and after a session once. That number is your sweat rate and it changes everything.
Why is water on its own not enough?
Sweat is not water. It is water with salt in it, and a fighter who sweats heavily can lose several grams of sodium in a session. Drinking plain water replaces the volume but not the salt, so the concentration of sodium in your blood drops. The result is heavy legs, cramp, a foggy head, and in extreme cases a genuinely dangerous condition. It is also why you can drink two litres and still feel wrecked.
| Electrolyte | Typical loss per litre | What it does |
|---|---|---|
| Sodium | 500 to 1,500mg | Holds fluid in the blood, drives thirst, nerve and muscle signalling. The one that matters most. |
| Potassium | 150 to 300mg | Balances sodium inside the cell. |
| Magnesium | 10 to 20mg | Normal muscle function, electrolyte balance. Losses are small per litre but daily intake in the UK is often low. |
| Calcium | 20 to 40mg | Muscle contraction. Covered by diet. |
How do you work out your sweat rate?
Naked or in dry kit, after the toilet, before the session. Write it down.
Note how much you drank during the session. A 500ml bottle is 0.5kg.
Towel off first. Weight lost plus fluid drunk, divided by the hours, is your sweat rate in litres per hour.
If you lost a kilo, you need about 1.5 litres over the next few hours, with sodium, because you keep sweating and peeing after you stop.
per hour is a normal sweat rate for a fighter in a hot gym. Some heavyweights double it. That is why "drink when thirsty" fails: thirst lags the loss by half a litre or more.
What should a fighter drink before, during and after?
You want 400 to 600mg of sodium in it. A scoop of Flow State in 500ml carries 500mg sodium, 250mg potassium and 100mg magnesium on top of the performance ingredients, which is why the electrolytes were put in the pre-workout rather than sold separately.
Water is fine for sessions under an hour if you started topped up. Over an hour, or in a very hot room, add electrolytes to the bottle.
With food, which brings sodium and potassium with it. Sipping beats chugging: your body keeps more of it.
What does cramp in round three actually mean?
Usually that you started the session under-hydrated, sweated more than you drank, and your sodium ran low. Occasionally that a muscle has been worked to exhaustion. Almost never that you need more bananas. If you cramp regularly, the fix is the pre-session electrolyte load and a sodium source during the session, and it usually works within a week.
None of this applies during a water cut, where the goal is temporarily the opposite. But it applies double after the weigh-in. A fighter who rehydrates with plain water fights flat. Sodium first, then water, then carbohydrate.
Sweat is salt water. Replace both.
Are sports drinks good for fight training?
Most contain too little sodium, around 200mg per 500ml, and a lot of sugar. They are better than plain water but not built for a heavy sweater. Check the sodium figure.
Is too much sodium a problem?
For a heavy sweater who trains daily, no. You are losing several grams a session. The people who need to limit salt are not the ones losing two litres of sweat in a boxing gym.
Do electrolyte tablets work?
Yes, if they carry enough sodium. Many are 200 to 300mg per tablet, so you may need two. The advantage of having electrolytes in the pre-workout is that it is one scoop and it is already in the routine.
Flow State before. Reset after.
A stim-free pre and the martial arts recovery formula, built for people who train every day and get tested. Full doses, every one on the label, nothing from the WADA Prohibited List.
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