Weight cutting in the UFC is the practice where fighters rapidly lose weight before the official weigh-in to qualify for a lower weight class, then regain much of that weight before the fight itself. This is done to gain a size and strength advantage over opponents who naturally weigh less in that class

. There are two main types of weight cutting:

• Gradual loss of fat and muscle over weeks leading up to the fight.
• Rapid loss of water weight in the final days before weigh-in, often through dehydration techniques such as sweating in saunas, wearing sweat suits, restricting fluids, and manipulating diet (carbohydrate and sodium intake)

Typically, UFC fighters lose around 6-7% of their body weight in the 72 hours before weigh-in and then regain approximately 9-10% of their weight in the 24-36 hours after weigh-in before the fight

. For example, a fighter might weigh in at 155 pounds (lightweight limit) but enter the cage closer to 165-170 pounds after rehydration and refueling

. While weight cutting can provide a competitive edge by allowing fighters to be bigger and stronger than their opponents in the same weight class, it carries risks such as dehydration, reduced athletic performance, kidney damage, and in extreme cases, serious health consequences including heat stroke or death

. Despite these risks, weight cutting remains a common and strategic practice in UFC and other combat sports