Dana White has gone on record saying he feels UFC featherweight champ, Max Holloway, should move up a weight class due to his recent “health scare”, saying he is too big for 145.

What is “cutting weight” and what are the health consequences?

What is weight cutting

To get a competitive edge athletes are required to “cut weight”, which means to temporarily dehydrate themselves to “make weight” and rehydrate themselves prior to the bout.

Effects of dehydration on the brain

During severe acute dehydration, the osmolality of extracellular fluid increases, and decreases blood volume in the brain. The brain will compensate by increasing cerebrospinal fluid (CSF) volume (Kempton 2007).
“Increased CSF volume could allow the brain to move further in the cranium following a blow to the head, thus increasing deceleration forces as the brain impacts the cranium. Rapid deceleration of the brain can cause confusion injuries (Besenski 2002).”


In mixed martial arts a fighter gets 24 hours to rehydrate, with the goal to replenish all of the lost water. In a study, Jetton found that 39% of MMA fighters were considered still dehydrated by the time of the fight.

While more research would need to be done to determine the hydration levels of elite fighters, it is clear that competing in a compromised state will put the athlete at a higher risk for injury.

Organizations such as @onechampionship have altered their weigh-ins to include hydration tests, so it is impossible to perform classic weight cuts.

States such as California are attempting to reduce drastic weight cuts by recommending fighters move up a weight class if they gain >10% of their fight weight by the time they compete.

Dr. Mike Piekarski, DPT
BJJ Black Belt
Former MMA Fighter

1. Besenski N (2002): Traumatic injuries: Imaging of head injuries.
Eur Radiol 12:1237–1252.
2. Jetton, A. M., Lawrence, M. M., Meucci, M., Haines, T. L., Collier, S. R., Morris, D. M., & Utter, A. C. (2013). Dehydration and acute weight gain in mixed martial arts fighters before competition. The Journal of Strength & Conditioning Research, 27(5), 1322-1326.