Effects of Different Rapid Weight Loss Strategies and Percentages on Performance-Related Parameters in Combat Sports: An Updated Systematic Review

Abstract

Most combat sports (CS) are structured in weight categories, and it is very common to carry out body weight adjustment strategies in order to compete in lower weight categories. For this reason, different rapid weight loss (RWL) strategies are usually performed to pass the pre-competition weigh-in test, and then a replenishment of fluids and carbohydrate-rich foods is conducted in an attempt to recover the weight and avoid a performance loss. In this context, no clear references have been found on whether these types of strategies have negative effects, impairing the athlete’s combat and/or physical performance. For this reason, the aim of this study was to review the scientific literature on the effect of rapid weight reduction strategies on the performance of CS athletes. A literature search was performed through four different databases (PubMed, SPORTDiscus, Web of Science and ScienceDirect). Four inclusion criteria were established as follows: (1) the subjects had to be competitors in the CS and carry out RWL strategies; (2) at least two measurement points, that is, normal conditions and dehydration condition; (3) measurements in a real competition or simulating the same conditions; (4) original research articles written in English or Spanish and available in full text. Finally, a total of 16 articles were finally included in this research. All subjects (n = 184) were athletes from combat disciplines, with a minimum of 3–4 years of practice, as well as with certain experience in RWL. Six of the studies reported that an RWL strategy of around 5% of body weight loss did not affect performance parameters. However, the other ten studies with RWL between 3 and 6% or even higher reported negative effects or impairments on different parameters related to performance and/or athlete’s psychophysiology, such as perceived fatigue, mood states, strength and power production, as well as changes in hormonal, blood and urine parameters, body composition, or the kinematics of the technical gesture. Although there is still no clear answer to the issue approached in this research, in general terms, it seems that in order to guarantee an acceptable athletic performance of the competitor, the weight loss should not exceed 3% to ≤5% of body weight together with ≥24 h for adequate (or at least partial) recovery and rehydration processes. In addition, it is highly recommended to lose weight progressively over several weeks, especially focusing on competitions lasting several days, as well as multiple rounds or qualifying stages.

The Practice of Weight Loss in Combat Sports Athletes: A Systematic Review

“…Therefore, athletes need to gain more advantages (e.g., height, arm span, strength) through WL to increase their possibility of winning competitions. While losing weight may not lead to intrinsic performance improvements [56][57][58][59] or a higher probability of winning [60][61][62], they believe it will lead to an advantage [63].…”

“…Except for the studies of Sambo, MMA, and Muay Thai athletes, all studies reported that the athletes' habitual WL was less than 5%, which is in line with the above research recommendations. Although previous studies addressing the effects of RWL on physiological parameters have produced conflicting data, demonstrating negative [69][70][71], positive [72], and negligible [72,73] effects, some systematic reviews and meta-analyses have shown no or negative effects of RWL on athletic performance [56][57][58]74].…”

Relações da hidratação no período pré e pós competições em atletas de artes marciais: revisão narrativa da literatura

“…Neste sentido, o estudo de Aranda et al (2023), uma revisão sistemática da literatura que objetivou trazer os efeitos que as diferentes estratégias de perda de peso poderiam trazer na saúde e performance do atleta, utilizou um total de 16 estudos, totalizando uma amostra de 184 atletas, sendo estes com pelo menos três anos de prática em esportes de combate e também uma experiência prévia em perda de peso rápida.…”

“…Obteve como resultado que a perda de peso entre 3 -5% da massa corporal total do atleta seria o ideal para a performance física e psicológica, trazendo ainda que se esta perda for gradual e o período de recuperação entre pesagem e luta for de >24h, seria menos prejudicial a saúde do atleta, pois o mesmo conseguiria atingir o peso e hidratar sem grandes intercorrência e sem prejuízos na capacidade física e funcional (Aranda et al, 2023).…”

Effects of short-term pre-competition weight loss on certain physiological parameters and strength change in elite boxers

“…Moreover, in combat sports, the reaction times and hit accuracy rates of competitors who chose to lose more than 5% of their body body mass were negatively affected [ 10 ]. Therefore, it seems to be a better choice at this stage to lose body mass gradually over a few weeks in competitions or qualifiers that last a few days [ 11 ]. In the case of boxers, this has not been investigated in depth.…”