Rapid Weight Loss in Combat Sports: Health Risks, Performance Trade-Offs, and Evidence-Based Weight Management — A Scoping Review

Abstract

Background: Rapid weight loss (RWL), commonly referred to as weight cutting, is a widespread practice in combat sports, where athletes attempt to qualify for lower weight categories before regaining body mass prior to competition. This practice combines chronic energy restriction with acute strategies to manipulate body water, glycogen stores, gastrointestinal contents, sodium intake, and body temperature, raising concerns regarding athlete health, performance, and safety.

Aim: To map the current evidence regarding the prevalence and methods of RWL in combat sports, its health and performance consequences, the relationship between post-weigh-in weight regain and competitive success, and evidence-based strategies for safer weight management.

Material and methods: This scoping review was conducted in accordance with the Joanna Briggs Institute methodology and the PRISMA Extension for Scoping Reviews (PRISMA-ScR). Peer-reviewed studies and consensus statements addressing boxing, mixed martial arts, wrestling, judo, taekwondo, Brazilian jiu-jitsu, kickboxing, Muay Thai, sambo, and other weight-category combat sports were included and synthesized.

Results: The evidence indicates that RWL is highly prevalent across combat sports. Common methods involve dehydration, energy restriction, heat exposure, and manipulation of diet and body fluids. Acute risks include dehydration, electrolyte imbalance, renal stress, acute kidney injury, impaired thermoregulation, endocrine disturbances, low energy availability, sleep disruption, fatigue, mood changes, disordered eating, and symptoms overlapping with concussion. Evidence linking rapid post-weigh-in weight regain with competitive success is inconclusive.

Conclusions: Rapid weight loss remains a highly prevalent but potentially harmful practice in combat sports. Safer weight management should emphasize long-term body mass planning, limiting acute weight loss, avoiding extreme dehydration and thermal or pharmacological methods.