Dehydration and Acute Weight Gain in Mixed Martial Arts Fighters Before CompetitionJetton, Adam M.1; Lawrence, Marcus M.1; Meucci, Marco2; Haines, Tracie L.1; Collier, Scott R.1; Morris, David M.1; Utter, Alan C.1Journal of Strength & Conditioning Research: May 2013 - Volume 27 - Issue 5 - p 1322–1326 doi: 10.1519/JSC.0b013e31828a1e91 Original Research Abstract Author Information Abstract: Jetton, AM, Lawrence, MM, Meucci, M, Haines, TL, Collier, SR, Morris, DM, and Utter, AC. Dehydration and acute weight gain in mixed martial arts fighters before competition. J Strength Cond Res 27(5): 1322–1326, 2013—The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters before competition. Urinary measures of hydration status and body mass were determined approximately 24 hours before and then again approximately 2 hours before competition in 40 MMA fighters (mean ± SE, age: 25.2 ± 0.65 years, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). The AWG was defined as the amount of body weight the fighters gained in the approximately 22-hour period between the official weigh-in and the actual competition. On average, the MMA fighters gained 3.40 ± 2.2 kg or 4.4% of their body weight in the approximately 22-hour period before competition. Urine specific gravity significantly decreased (p < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the approximately 22-hour rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of >1.021 immediately before competition indicating significant or serious dehydration. The MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24-hour period before competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating before competition and subsequently are competing in a dehydrated state. Weight management guidelines to prevent acute dehydration in MMA fighters are warranted to prevent unnecessary adverse health events secondary to dehydration. 1Department of Health, Leisure, and Exercise Science; Appalachian State University, Boone, North Carolina; and 2Department of Health Sciences, University of Rome “Foro Italico,” Rome, Italy Address correspondence to Alan C. Utter, firstname.lastname@example.org. Copyright © 2013 by the National Strength & Conditioning Association.