Weight Cut

Last updated: April 22, 2026

What is a weight cut in MMA?

In MMA, a weight cut is the short-term weight loss a fighter goes through in the final week before a scheduled bout. It exists because fights are contested in weight classes, and most promotions weigh fighters roughly 24 to 36 hours before the fight itself. That gap is what makes the practice possible. A fighter drops weight, hits the scale at the upper limit of their division, and then rehydrates and refuels before competing.

The distinction between “a weight cut” and “weight cutting” is small but real. Weight cutting is the general practice; a weight cut is one specific attempt, usually tied to one fight. When fans or commentators talk about “Khabib’s weight cut” or “a brutal weight cut,” they mean the particular process that fighter went through for that particular bout.

A weight cut is not the same as losing weight in a general sense. The bulk of the weight shed in the final days comes from water, not fat, and it is meant to come back on quickly. A fighter who weighs in at 170 pounds on Friday morning often enters the cage on Saturday night somewhere between 180 and 185 pounds, according to Sweet Science of Fighting’s breakdown of the welterweight division.

How a weight cut works

A weight cut usually runs in two phases. The first is chronic weight loss: several weeks of reduced calories, controlled training volume, and steady fat loss to get close to the target weight. The second is acute weight loss, which happens in the final five to seven days and focuses almost entirely on water.

During fight week, fighters typically water-load, meaning they drink large volumes of water for several days so the body shifts into a flushing state. Intake is then cut sharply, while the body continues to shed fluid. Sodium and carbohydrates are also reduced, since both hold water in the body.

The last pounds come off through sweating. Saunas are the most common tool, along with sauna suits worn during light cardio and the occasional hot bath. Oliver Barley and colleagues at Edith Cowan University, in research summarized by IMMAF in 2020, reported that 76% of MMA fighters used saunas during their cuts and 63% used sweat suits, higher than in any other combat sport studied.

Once a fighter passes the weigh-in, the cut is over. The hours between the scale and the fight are spent drinking fluids with electrolytes, eating easily digestible carbohydrates, and gradually returning to something close to normal eating. Some fighters have used IV rehydration in the past, though this is banned under UFC anti-doping rules and by most athletic commissions.

How much weight do MMA fighters cut?

Most professional MMA fighters lose between 5% and 8% of their body weight during fight week, according to research summarized by Sweet Science of Fighting and the 2019 narrative review in Sports published on PMC. For a lightweight fighting at 155 pounds, that works out to roughly 8 to 12 pounds in the final week. For a welterweight at 170, it can mean 10 to 15 pounds. Extreme cuts push higher.

Some well-known examples sit at the top end of that range. Georges St-Pierre reportedly cut 20 to 30 pounds in the final week of a welterweight camp. Khabib Nurmagomedov’s lightweight cuts were notoriously grueling. Coaches described drops in the 20-plus pound range. Cris Cyborg, before one of her early UFC appearances, lost 26 pounds in three days to reach 140 pounds. Darren Till’s cut to 170 pounds before his 2018 fight with Stephen Thompson, documented in a Paddy Power video, showed him crawling out of a sauna and temporarily losing his vision before ultimately missing weight by 3.5 pounds.

A 2024 Two Percent article by Michael Easter, citing performance nutritionist Tyler Minton, reported that some UFC fighters lose up to 20 pounds in the 120 hours before a weigh-in, then regain most of it in the 36 hours before the fight.

Weight cut vs. weight loss

These terms are often confused, especially by newer fans. They describe different things.

	Weight cut	Weight loss
What is lost	Mostly water	Fat, sometimes muscle
Timeframe	Days (final week of camp)	Weeks or months
Goal	Hit a weigh-in number, then regain	Permanent or long-term change
Reversible	Yes, and intentionally so	Not the point
Common in	Combat sports, rowing, horse racing	General population, most sports

A fighter can do both in the same camp. Chronic weight loss over the training cycle reduces body fat. The acute weight cut in the final week sheds water to make the division limit. The acute cut is the part unique to combat sports, and the part that draws most of the controversy.

Risks and regulation

Weight cutting has been linked to several fighter deaths in combat sports. Chinese MMA fighter Yang Jian Bing died in December 2015 from cardiopulmonary failure during a dehydration-based cut for a ONE Championship fight, as reported by MMA Fighting at the time. Brazilian MMA fighter Leandro Souza died in 2013 during a cut. In Muay Thai, Scottish fighter Jordan Coe died in 2016 and Australian teenager Jessica Lindsay died in 2017, both from severe dehydration.

Research has also flagged broader health and performance costs. A study cited by Christopher Kirk in The Conversation found that 43% of fighters at a 2017 UK MMA event were severely dehydrated before competition, with readings comparable to weight-cutting fatalities in 1990s US collegiate wrestling. Repeated large cuts have been associated with kidney damage, endocrine dysfunction, eating disorders, and increased concussion risk.

Regulatory responses have varied. ONE Championship banned weight cutting by dehydration in 2015 after Yang’s death, introducing a system in which fighters log their walking weight daily and must pass a urine specific gravity test (≤1.025) before being allowed to weigh in. In November 2024, according to the Bangkok Post, ONE added a 20% purse fine for fighters who fail to make weight or pass hydration within the first hour of the three-hour testing window. The California State Athletic Commission has tightened rules on allowable cuts since 2017. Most other major promotions, including the UFC, still rely on traditional same-day or day-before weigh-ins.

Debate continues over whether the competitive advantage from cutting outweighs the performance cost. Research from Edith Cowan University, cited by IMMAF, found that fighters who cut more weight lost their fights more often than those who cut less, and that fighters who did not severely restrict calories during rapid weight loss tended to win more often than those who did.

Frequently Asked Questions

Can a fighter cut weight without dehydration?

Yes, though it takes longer. Chronic weight loss through diet and training can bring a fighter close to their division limit before fight week, reducing the need for acute water loss. ONE Championship’s system is built around fighters staying at their walking weight year-round.

What happens if an MMA fighter misses weight?

They typically forfeit a percentage of their purse to their opponent (usually 20-30%), lose eligibility for post-fight bonuses, and, in the case of title fights, forfeit the belt. The fight may be renegotiated as a catchweight bout or cancelled entirely.

Do heavyweight fighters cut weight?

Most do not, or cut only a few pounds. The UFC heavyweight limit is 265 pounds, and most heavyweights walk around below that figure. Light heavyweights (205 pounds) and below generally do cut.

How long does an MMA weight cut take?

The final acute phase usually runs five to seven days. The fat-loss portion of a camp can take eight weeks or longer, depending on how far the fighter is from their target.

Is weight cutting banned anywhere in MMA?

Dehydration-based cutting is banned in ONE Championship. Most other major promotions regulate it through weigh-in timing, hydration testing in some jurisdictions, and athletic commission rules on allowable weight drops.

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Sources

1. Wikipedia. “Weight cutting.” Accessed April 2026.
2. Park, S. et al. “Self-reported methods of weight cutting in professional mixed-martial artists.” Journal of the International Society of Sports Nutrition, 2019.
3. Barley, O. et al. “The Current State of Weight-Cutting in Combat Sports.” Sports (PMC6572325), 2019.
4. Kirk, C. “Mixed martial arts and the danger of extreme weight cutting.” The Conversation, 2021.
5. IMMAF. “How Severe is Weight Cutting in MMA?” October 2020.
6. Morehen, J. “Weight cutting in combat sports: What is it and how can you minimise the risks?” Science for Sport, March 2025.
7. ONE Championship. “Martial Arts: Weigh-In and Hydration Rules.” Official site.
8. Bangkok Post. “ONE Championship shakes up weigh-in rules, implements new fine system.” November 2024.
9. Cronkite News. “‘Fight before the fight’: MMA warriors battle to beat the scale in grueling process of cutting weight.” December 2023.

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