Original Research: PDF OnlyWeight-Cutting Implications for Competition Outcomes in Mixed Martial Arts Cage FightingBrechney, Grant C.1; Chia, Eevon1; Moreland, Ashleigh T.1,2Author Information 1School of Exercise Science, Sport and Health, Faculty of Science, Charles Sturt University, Bathurst, New South Wales, Australia; and 2Exercise and Sport Science Discipline, School of Health and Biomedical Science, RMIT University, Melbourne, Victoria, Australia Address correspondence to Grant C. Brechney, [email protected]. Journal of Strength and Conditioning Research: September 25, 2019 - Volume - Issue - doi: 10.1519/JSC.0000000000003368 Buy PAP Metrics Abstract Brechney, GC, Chia, E, and Moreland, AT. Weight-cutting implications for competition outcomes in mixed martial arts cage fighting. J Strength Cond Res XX(X): 000–000, 2019—Weight cutting is common among amateur and professional mixed martial arts (MMA) competitors because of the belief that it provides an advantage in combat sports. This study aimed to identify whether fight outcome (win vs. loss vs. type of loss) was influenced by magnitudes of body mass (BM) lost through weight cutting and BM regained before the fight after official weigh-in in amateur and professional MMA athletes with previous weight-cutting experience. Body mass data were collected using self-report from 75 MMA athletes (59 amateur and 16 professional) before commencing weight-cutting practices 7 days before weigh-in, by the regulating body at their official weigh-in 24 hours before the fight and through direct measurement immediately before competition. Data were analyzed according to win; loss by technical knockout or knockout (KO); loss by submission; or loss by the judge's decision. Athletes who lost their fight cut significantly more BM (10.6%) compared with athletes who won (8.6%) (p = 0.04, d = 0.48, 95% confidence interval [CI] = 0.02–0.93), but there were no differences between types of loss. There were no significant differences in recovered BM between athletes who won (6.8%) vs. lost (7.4%), or type of loss. Furthermore, there was a significant relationship between greater magnitudes of BM cut and greater likelihood of losing the fight (B = −0.12, P = 0.048), odd ratio 0.89 (95% CI: 0.79–1.00). This study provides the first line of evidence that excessive weight cutting may be detrimental to fight outcome in MMA. Copyright © 2021 by the National Strength & Conditioning Association.