In this post I’ll be breaking down 2 methods of water manipulation strategies used in Muay Thai, discussing the pros, cons and risks involved.

There is no right or wrong as its all pretty insane, but there is always more than one way to skin a cat. It comes down to personal preference of each individual fighter, and also the way they have been coached or become a custom to.

I have seen all types of weight cut strategies, and I know what I prefer my fighter clients to do, but I’ll let you be the judge and you can comment below if you have experience in either and let me know which you think is a better way to go.


In weight classed sports like Muay Thai, wrestling, MMA, fighters are classed in weight categories to ensure a evenly matched fair fight.

The most common reason a fighter may go down in weight class simply out of opportunity to fight.

A promoter will call gyms looking for a fighter a certain weight, if a fighter is too heavy but wants the opportunity (or money) they opt to cut weight and take the fight.

In some cases, fighters practice weight cutting techniques believing their chances of success will increase by coming down to a lighter weight class.

In Muay Thai, fighters weigh in the day before fighting, so this leaves room for fighters to cut loads of weight, then within 24 hours put the weight back on gaining an advantage over the opponent.

However ironically, if done wrong weight cutting can actually impair performance or endanger the fighter’s health.

Fighters are classed by weight category to ensure even and fair competition.

Ideally fighters hope to replenish body fluids, electrolytes, and glycogen (the stored version of carbohydrates) in the brief period between the weigh in and competition.

Re-establishing bodily fluids, however can take a minimum of 24 hours and up to 72 hours to replenish glycogen.

If you have not supported your muscle tissue adequately during the weight cut, you may have done tissue damage which can take even longer to fully recover.

In this post, first we take a look at the more traditional method of fluid manipulation – Sweat suit and exercise. Second, we take a look at water manipulation based on fluid balance physiology.


Water cutting in general is not safe but is a necessary evil in today’s weight classed sports.

Side effects like muscle cramps and low energy are manageable, but when things roll over into dehydration and heat stroke, that’s is nothing to take lightly.

Its important that people know that as you lose valuable fluids, the blood thickens and your heart begins to pump faster.

The blood will eventually get too thick for the kidney’s to filter, and without rehydrating, you could suffer permanent kidney and brain damage and ultimately go into complete circulatory collapse- resulting in death.

If you’re going to be entering this kind of silliness for the love of your sport, be aware that just because these practices are commonly used, doesn’t mean it is safe.


During November 7-December 9, 1997, three previously healthy collegiate wrestlers in different states died while each was engaged in a program of rapid weight loss to qualify for competition.

In the hours preceding the official weigh-in, all three wrestlers engaged in a similar rapid weight-loss regimen that promoted dehydration through perspiration and resulted in hypernatremia.

The wrestlers restricted food and fluid intake and attempted to maximize sweat losses by wearing vapor-impermeable suits under cotton warm-up suits and exercising vigorously in hot environments – The National Centre for Biotechnology Information

wieight cutting

In this image, guys are using odd weight cutting strategies which can end up a disaster.

Now, death is pretty uncommon. But you can see the combination of heat, exercise and fluid deprivation creates a dangerous physiological effect on the body. However the more common result of using these strategies incorrectly is being ill prepared to compete.


I want to get something clear from the start. Sweat suits do not burn fat, that’s a common myth.

Running in a sweat suit will only cause profuse sweating as the core temperature of the body rises. In Thailand this is the preferred and common approach and I have seen people lose up to 4kgs in a 30 minute run.

While you are exercising in the suit, temperatures can climb up to 100+ degrees within 20 minutes in Thailand heat and can cause death.

Pros: Running in a sweat suit is simple and easy to do. If you don’t have a fancy “top king” sweat suit, people have been known to wrap themselves in garbage bags or plastic wrap and go running.

Cons: The act in itself of inhibiting your skin to breath and release heat while exercising is energy consuming and dangerous.

The combination of core temperatures reaching upwards of 100+ degrees, excessive fluid losses and exercise can result in severe muscle cramps, dehydration, heat stroke, or worse.

Tips: Do not drastically cut food intake if you are going to use this method.

The point of running in the sweat suit is to lose water; there is no need to combine this with starvation.

The body uses up to 90% of all energy to regulate its self and maintain safe temperatures so it needs a steady supply of nutrients to keep up with these dangerously high demands.

How to enhance the process: Dropping your carbs will help lose water. Avoiding salt will help. After each session in a sweat suit you need to replace lost vitamins and minerals.

A multi vitamin is good for this. Electrolyte powders are to be avoided as they are mostly salt.



A more technical but efficient way to cut is water manipulation based on fluid balance physiology.

This is the same water manipulation strategy I use with all of my coaching clients. It involves increased water intake for short periods of time which leads to increase in urinary fluid losses for several days.

Essentially a fighter will increase water, and then reduce each day until intake is zero by weigh in day. In order to increase fluid losses salt and carbohydrates are lowered and monitored.

Pros: A safer way to lose water weight. Less risk of heat stroke, less muscle tissue damage, cramps. There is no need to run in a sweat suit as your body will do most of the work itself. This saves you a huge amount of energy.

This method is handy if you are travelling to fight, live in cold conditions, or if you like to rest on the week leading up to your fight.

Cons: It can be dangerous if done incorrectly. Drinking large amounts of water can lead to hyponatremia. This means having too much water relative to sodium content. With this method, you really need to be tapering off your training.

If you have a coach who demands you run is a sweat suit while training hard in the week of your fight, this method is quite uncomfortable and dangerous.

Tips: To finish off this method, on the day prior to weigh in do a couple of short sauna sessions. You can normally lose the last 1-1.5kgs in a 20-30 min sitting. On the day of weigh in, use the sauna as needed to make weight. When doing a cut like this, it’s important to top up on vitamins and minerals each day. There is no doubt you’re going to feel like dog poo, but the healthier you are the better and faster you will recover.



My client Eddie Vendetta is the best example of how well this method can work when done properly. When Eddie first started on The Lean Performance Diet over he was around 86kgs and he needed to reach his weight class of 72kgs within 4 weeks.

His previous weight cut strategy of exercise and sweat suit combined with starvation was becoming less effective and dangerous so he asked me to help.

This was his biggest weight cut ever but he made it easily.

Not only that, after his check weight he followed my specific rehydration plan and sprung back up to 83kgs within 24 hours. He was able to do this because he prepared his body with high amounts of nutrients, vitamins and minerals for weeks prior to the cut and was in great shape. In Eddie’s words “I had never had so much strength and power for a fight” pretty amazing right?

Keep in mind, extreme weight cutting is not for everyone I can tell you that! Most people can do 2-5kgs. But it takes a seriously strong mind to power through a 10kg+ weight cut. With either method of cutting one thing is 100% certain.

The more physically fit and conditioned you are the better you will handle the process, the better you’ll feel once rehydrated.

People who are not in optimal condition will find either method far more challenging.

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