How to cut weight in 24 hours

If you are reading this the day before a weigh-in, the most useful thing I can give you is a way to read the gap in front of you, because the size of that gap decides whether the next 24 hours are a technical problem or a medical one.

The last day gets all the attention because it is the visible part. It is also the part with the least available weight in it and the most risk attached, and almost everything that determines how it goes was decided in the weeks before.

What the last day is actually made of

Three things can still leave the body in 24 hours, and none of them is fat.

• Gut content. Under 1 percent of body mass, and the cheapest weight in the whole cut. It costs nothing in performance if the fibre reduction started several days earlier. Started on the last day, it does nothing.
• Glycogen and its bound water. Every gram of stored muscle glycogen carries roughly 3 grams of water. Depleting it releases that water, and it also removes the fuel you are going to need. Real, but expensive.
• Body water. The largest of the three and the one everyone means when they say cutting weight. Sodium and fluid manipulation set this up across the preceding days. The controlled water loading protocol is worth about 0.6% of body mass over simply restricting fluid, which is far less than the folklore claims.

Add those up honestly and you get a number in the region of 3 to 4 percent for a prepared athlete. That is the ceiling in the research, and it is roughly what a competent camp plans for.

Why you cannot copy someone else's last day

A coach once spent 2 camps standing next to me while I made weight with Oleksandr Usyk and Denys Berinchyk. He watched everything and wrote it all down. Sensible, and I had no objection.

About a year later he took two of his own boxers abroad for a fight and ran what he had written. By his plan both should have woken up on weight on the morning of the weigh-in.

One woke up 2.5 kg over. The other 3.2 kg over.

Nothing in the protocol was wrong. It had produced two world-level weigh-ins in front of him. It was simply built around two specific men, their body composition, their sweat rates, their history of previous cuts and how they had been fed for the 8 weeks before it. Transplanted into two different bodies it did not transfer, and the error only became visible at the point where there was no time left to correct it.

A protocol is an answer to a particular athlete. Written down and carried to another one, it is just a document.

Read your gap first

Before doing anything, weigh yourself first thing in the morning, without clothes, after using the bathroom, on the same scale you have been using. Then work out the gap as a percentage of your body weight rather than in kilos, because the percentage is what the physiology responds to.

A 70 kg fighter who is 1.2 kg over is in the first row and should stop worrying. The same fighter 4.5 kg over is in the last one, whatever anybody in the gym is telling him.

The part nobody wants to hear

If the gap is large, the honest options are these, and there are only three.

Negotiate a catchweight. Unglamorous, and it costs something. It also keeps you healthy and keeps the fight. This is a conversation for your manager to have early rather than for you to have at the scale.

Miss the weight and take the penalty. In almost every case the bout still happens, with a purse deduction and sometimes a glove or rehydration condition attached.

Withdraw. The option nobody lists, and occasionally the only correct one.

What is not on that list is removing 6 percent of your body weight overnight from an athlete who has already been in deficit for weeks. That combination, a large gap and a depleted fighter, is the one that appears in every serious case combat sports has had.

The camp where I said stop

A boxer I worked with had a run of good paydays and relaxed. When I arrived for camp he was 11 to 12 kilos above his own off-season weight, which is a different problem entirely from being above his fighting weight.

That camp was the hardest I have run. It included everything I spend the rest of this website arguing against: sweat suit on the treadmill in the final week, bag work in the suit, sauna. None of it was right. We were salvaging a situation that should never have been created, and salvage work looks nothing like a plan.

Several days out, the coach and I could both see where it was going, so we did the honest thing early: we asked the other side to agree a higher weight for the bout. They accepted. That should have been the end of it.

With 24 hours to go we still had a few pounds left, and the weight simply stopped moving. That happens. A body that has been pushed for weeks reaches a point where it stops cooperating, and no amount of additional pressure changes the answer.

We ran a hot bath. In it, he began to lose consciousness.

He weighed in over the agreed figure and we paid the penalty for missing weight. He fought, and he won, and the performance was poor. Everyone in that changing room knew why.

Afterwards I told him the terms for any future camp: if he wanted me to come, he had to be at a set weight before I arrived, 9 kilos below where he had been this time. Not a suggestion. The condition of the work.

I include this because the section above is easy to write and hard to do. The honest options in a bad situation are unglamorous and they cost money, and we took two of them in one camp, the renegotiation and then the penalty, and it was still the closest I have come to something going badly wrong. The mistake had been made months earlier, long before that bathroom, when nobody was watching the weight at all.

When to stop, without argument

These are not signs to push through. If any of them appear, the cut is over and the conversation is with a doctor.

• Confusion, disorientation, or behaviour that is not normal for that person
• Chest pain, or a heart rate that will not settle at rest
• Repeated vomiting
• Fainting, or near-fainting on standing
• Cramping that will not release
• Having stopped sweating while still in heat
• A headache that keeps building, especially after heavy fluid intake, which can indicate hyponatremia and where the instinctive response of giving more fluid is exactly wrong

The morning after the scale matters more

Whatever came off has to go back on, and how much of it returns is what the research links to actually winning rather than merely competing.

Check your bout agreement first. A rehydration clause caps how much you are allowed to put back on, and it changes the target.

Decide the number you are aiming to be back at before the weigh-in, not after it. Electrolytes first at around 150 percent of the fluid lost, then food in an order the gut will accept. The full sequence is here, and it is the half of the job most fighters have never planned at all.

Next time

The reason this article cannot give you a bigger number is that the last 24 hours is a settlement, not a solution. It cashes out decisions taken in week one of camp.

If you have arrived here twice with the same problem, the problem is not the final day. Start with which division you belong in, then run your own numbers, and build the descent so that the day before the weigh-in is boring.

In a properly run camp, it is. That is what a good one looks like from the inside: nothing happening, on purpose.

Common questions

How much weight can you lose in 24 hours before a weigh-in?

Published guidance puts a manageable acute reduction at roughly 4.4% of body mass at 24 hours out. On an 80 kg athlete that is around 3.5 kg, and it assumes the earlier phases of the descent were done properly.

How can I cut weight fast for a fight?

Fast weight loss before a fight is water and gut content, and there is a ceiling on it. The 2025 ISSN position stand puts suitable acute losses at about 4.4 percent of body mass in the final 24 hours before the weigh-in, with sauna, hot baths and wraps kept to about 2 to 4 percent within that day. Anything beyond that has to come off in camp, weeks earlier.

How do you cut water weight fast?

Body water is reduced through sodium and fluid manipulation across the days before the weigh-in, not through improvised sweating on the final day. The controlled water loading protocol is worth around 0.6% of body mass over simple fluid restriction.

What if I am still 4 kilos over the day before?

At that point it is no longer a weight problem, it is a decision. The realistic options are a catchweight, a withdrawal, or accepting a penalty for missing weight. Removing 4 kilos in a day from an athlete who is already depleted is where combat sports have lost people.

Does a sauna help you make weight?

It removes water, which is why it is used, and it is also where the risk concentrates. Heat is a correction tool for a small residual amount, under supervision. It is not a method for closing a large gap.

Can you use another fighter's weight cut protocol?

No. A protocol is built around one athlete's body composition, sweat rate, cut history and how he was fed through camp. Copied onto a different athlete it commonly fails at the point where there is no time left to correct it.