Weight cutting, and the associated risks and advantages/disadvantages is a topic of great focus in the combat sports world. Most combat sports athletes will engage in rapid weight loss (RWL) prior to weigh-in, followed by rapid weight gain (RWG) leading up to the scheduled bout. 


The health risks associated with these practices have been identified in previous studies, however the perceived advantages come match day have led to most athletes continuing RWL/RWG practices. 


Previous research into the effect on performance has been conflicting. Some studies have shown improved performance following greater RWL/RWG in MMA, wrestling and judo, some have shown decreased performance in MMA, whereas other studies in boxing, wrestling, taekwondo and MMA have shown no difference. 


This study analysed 700 professional MMA bouts in California between 2015 and 2019, and cross-referenced the absolute and relative weight regain with the fight outcome. This was a significantly larger sample size than that used in previous studies.


% weight gain was positively associated with fight outcome, with each 1% gain in weight leading to a 4.5% increase in the probability of winning.


Although this is only one study in a body of evidence with mixed findings, it does lend weight to the perception that despite significant potential health risks, weight cutting can positively influence performance in professional MMA competition. This further highlights the need for quality education for athletes and coaches. If fighters are incentivized to aggressively cut weight then it is imperative that the methods they are utilising are as safe as possible. 


#weightcutting #rapidweightloss #rapidweightgain #mma #boxing #ufc #bellator #onefc


Faro, Heloiana, Dalton de Lima-Junior, and Daniel Gomes da Silva Machado. “Rapid weight gain predicts fight success in mixed martial arts–evidence from 1,400 weigh-ins: Weight regain and fight success in MMA.” European Journal of Sport Science just-accepted (2021): 1-30.

About the author

Sam Gilbert

Sam Gilbert is a registered physiotherapist with the Australian Physiotherapy Association (APA) and certified strength and conditioning specialist (CSCS) with the National Strength and Conditioning Association (NSCA). He holds a bachelor’s degree in Physiotherapy from Latrobe university (Melbourne, Australia) and a master’s degree in Exercise Science (Strength and Conditioning) from Edith Cowan University (Perth, Australia).

A 3rd Dan black belt in Shinkyokushinkai Karate under the World Karate Organisation (WKO), Sam participated for over 20 years in full contact competition, winning multiple state and national titles, and culminating in a 4th place in the heavyweight division of the Shinkyokushinkai World Cup in 2009.

As the co-founder and clinical director of Club 360, the premier multi-disciplinary health and fitness center in Tokyo, Japan, Sam has combined his practical experience with an in-depth study of sports performance in relation to combat sports, and strives to help other combat athletes reach their full competitive potential, whilst at the same time decreasing injury risk and increasing competition and training potential.

Add comment

By Sam Gilbert