SYSTEMATIC REVIEW published: 12 April 2022 doi: 10.3389/fphys.2022.830229 Edited by: Hassane Zouhal, University of Rennes 2 – Upper Brittany, France Reviewed by: Patrik Drid, University of Novi Sad, Serbia Abderraouf Ben Abderrahman, University of Manouba, Tunisia *Correspondence: Bianca Miarka miarkasport@hotmail.com Specialty section: This article was submitted to Exercise Physiology, a section of the journal Frontiers in Physiology Received: 06 December 2021 Accepted: 18 February 2022 Published: 12 April 2022 Citation: Mauricio CDA, Merino P, Merlo R, Vargas JJN, Chávez JÁR, Pérez DV, Aedo-Muñoz EA, Slimani M, Brito CJ, Bragazzi NL and Miarka B (2022) Rapid Weight Loss of Up to Five Percent of the Body Mass in Less Than 7 Days Does Not Affect Physical Performance in Official Olympic Combat Athletes With Weight Classes: A Systematic Review With Meta-Analysis. Front. Physiol. 13:830229. doi: 10.3389/fphys.2022.830229 Rapid Weight Loss of Up to Five Percent of the Body Mass in Less Than 7 Days Does Not Affect Physical Performance in Official Olympic Combat Athletes With Weight Classes: A Systematic Review With Meta-Analysis Clóvis De Albuquerque Mauricio 1 , Pablo Merino 1,2 , Rodrigo Merlo 1 , José Jairo Narrea Vargas 1,3 , Juan Ángel Rodríguez Chávez 1 , Diego Valenzuela Pérez 4 , Esteban Ariel Aedo-Muñoz 5 , Maamer Slimani 6 , Ciro José Brito 7 , Nicola Luigi Bragazzi 8 and Bianca Miarka 1 * 1 Department of Physical Education, Laboratory of Psychophysiology and Performance in Sports and Combats, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, 2 Núcleo de Investigación en Ciencias de la Motricidad Humana, Universidad Adventista de Chile, Chillán, Chile, 3 Universidad Norbert Wiener, Lima, Peru, 4 Escuela de Kinesiología, Facultad de Salud, Magister en Ciencias la Actividad Física y Deportes Aplicadas al Entrenamiento Rehabilitación y Reintegro Deportivo, Universidad Santo Tomás, Saniago, Chile, 5 Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Universidad de Santiago de Chile, Santiago, Chile, 6 Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy, 7 Department of Physical Education, Federal University of Juiz de Fora, Governador Valadares, Brazil, 8 Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, Toronto, ON, Canada Given the relevance of the effects that weight loss can generate on the physical performance in athletes, this study performed a systematic review with meta-analysis of the published literature on rapid weight loss (RWL) and examined its impact on the physical performance in Official Olympic combat sports athletes. The “Preferred Reporting Items for Systematic Reviews and Meta-Analysis” (PRISMA) guidelines were followed to ensure an ethical and complete reporting of the findings. PubMed, SPORT Discus, and EBSCO were the electronic databases explored for article retrieval and selection. The following string was applied: “RWL” OR “weight loss” OR “weight reduction” AND “judo” OR “wrestling” or “taekwondo” or “boxing” AND “performance.” Based on the quality analysis, conducted according to the “Tool for the assessment of study quality and reporting in exercise training studies” (TESTEX), ten articles achieved a score >6 points. The meta-analysis showed a significant difference in pre- vs. post- weight loss (p = 0.003) and no effects in pre- vs. post-power and strength performance analysis (p > 0.05 for both results). Based on our systematic review and meta- analysis of the literature, RWL up to ≤5% of the body mass in less than 7 days does not influence performance outcomes in Official Olympic combat athletes with weight classes, considering the strength and power measures. Keywords: rapid weight loss, diet, martial arts, dehydration, ergogenic aids Frontiers in Physiology | www.frontiersin.org 1 April 2022 | Volume 13 | Article 830229