This month’s AISTS Sport Medicine Podcast discusses the well-known practice of weight cutting in combat sports. Which techniques are used? Is it safe to do it?

Weight cutting is a very common practice in contact sports such as Taekwondo, Judo, Wrestling, Boxing and MMA. It is the practice of rapidly losing weight to fit in a certain weight category before a fight, and it is often achieved through extreme and very rapid dehydration techniques. Fighters can lose up to between 9 and 11 kg of body weight in the weeks leading up to a fight. What does science have to say about this? Is there a safe way to do it? What does the research show? Dimitrios Balomenos and Arthur Vignier from the 2018 Class have an interesting argument about this in this months’ AISTS podcast. Listen and join the conversation in the comments.

Welcome to Black belt podcasts. Today we will introduce you to a famous behavior among combat sport athletes : weight cutting.

Weight cutting is the practice of fast weight loss prior to a sporting competition. Fighters can lose as much as 9 to 11kg in the weeks leading up to a bout. Let’s dig up into this.

Martial arts combat sounds in the background

A1 – Hello man, it’s been a long time ! I saw you were competing in the +80 category and I didn’t expect you there? How come?
A2 – Hey man, yes, actually I wish I could compete in the under 80 but it’s too hard to lose all my kilos… so I will have to fight with the big guys!

A1 – Really ?! That’s gonna be challenging ! These guys weight more than 95kg. How much do you weight?
A2 – Well, right now I am around 85 but all of it is muscles : by fat percentage is only 5%.
A1 – Seriously … That’s not a problem at all ! I am in the middle of my weight cutting period and I already went from 88 to 83, both of us should have been under 80 for the weight-in tomorrow ! You’re not a junior … Haven’t you heard of techniques to lose weight ? Is your coach ignorant or what?
Come to the cloakroom and we can discuss this.

Background sound stops

A1 – Man you’re an elite fighter you need to be aware of rapid weight loss strategies?
A2 – Oh, I am actually … but are you really doing these acute techniques that your coach showed you or have you found a good weight loss management approach?
A1 – Of course acute; who wants to starve for a long period ? Take a look: First, you have to reduce your food and fluid intake. I am taking a spoon of peanut butter each meal then, as of today I will take only one per 24h. Then you need to ‘dry out’, which increases your body secretions. For this I usually use saunas and stay there for 45 minutes. While being in this hot environment, I also try to raise my metabolic rate by doing push-ups, crunches and so on … And then when I get too exhausted, I roll myself with a sweatsuit and towels to perspire. At this step, you may need someone to help you rip off the sweat so your body will produce some more.
A2 – That sounds awful. Have you thought about the consequences on your body? I read in a study of a guy named Khodaee that this dehydration can cause heart strain, kidney malfunction or risks of shock or coma. Athletes have even died from it.
A1 – Come on, if you eat and drink straight after the weigh-in everything will function well again.
A2 – Please grow up, first, as the body dehydrates, blood thickens and kidneys work harder to filter it. The organ cannot produce enough urine and this leads to kidney malfunction. And also if you are severely dehydrated, you’re gonna have a problem.
A1 – That’s only 1 out of a 1000 probably. Even a party is more dangerous for your kidneys & health than this.
A2 – Don’t be naïve ! That’s not all, I have also heard from literature reviews on the subject that even fast rehydration is dangerous because it can create edemas.
A1 – Oedi.. what ?
A2 – E – de -mas, it’s when your (already) little brain becomes smaller because there is less cerebral spinal fluid. Think of the brain having more room to bounce around the skull. You will get injured more easily for sure.
A1 – I don’t care about your medical scientific blabla, the psychological boost is so important.
A2 – Which psychological boost are your talking about, according to the sport science journal, it makes you angry, confused and depressed, which are not positive feeling in a competition right ?
A1 – That’s only one view. Choma also said that the cognitive effect on your mood is not sustained after you regain weight so you will be fine. On top of this, being angry before fighting can only make me more ready to fight. Also this is part of the sacrifices of a top-notch athlete !
A2 – Have you ever thought about your performance ? Do you really feel strong after all of this?
A1 – Of course! A study reported that winners reduced a higher amount of body mass compared to defeated athletes!
A2 – Ok and, if I tell you Mendes, Franchini and others describing decreased strength, power and performance then you will say again it’s nothing?
A1 – Even your beloved studies say it’s nothing : Reljik have found no significant change in aerobic capacity of 28 well-trained combat athletes. Also, my coach told me that most studies on that have a lot of methodological weaknesses so there is not a great level of evidence yet!
A2 – Alright, so let’s see who will get the best result! Do you wanna bet?

Off voice:
So no matter which strategy is being used, there are potential negative effects of rapid, aggressive weight loss that occurs close to competition. Also, it may be interesting to design some recommendations to fight this issue. First, the weight-in testing could be modified : One, with pre-season body composition measurements and allowing a maximum weight loss % or minimum body fat %, such as in NCAA wrestling. Another solution could be introducing Some hydration tests such as a “gravity strip” in addition to the classic weight-in. Another idea could be having random testing on competition day, such as the taekwondo federation’s one in 2018. Also an educational approach on weight monitoring techniques to effectively change athlete behaviour could be reinforced. These workshops could be illustrated with role models having moved up a weight class and are still being successful (Ilias Illiadis, Floyd Mayweather, Manny Pacquiao …)

You can find more AISTS Sport Medicine podcasts on our Soundcloud channel or on the Apple Podcast app. To learn more about the AISTS Master of Advanced Studies in Sport Management and Technology, visit

Photo Unsplash.

Experience the world of sport in the Olympic Capital

Participants attend several full-day workshops throughout the programme to experience sport. These sessions are delivered by the sport organisations and federations themselves and provide a unique hands-on experience and well as an ideal opportunity to connect to our alumni and experts working in the industry.