Effects of Weight Cutting on Exercise Performance in Combat Athletes: A Meta-Analysis

International society of sports nutrition position stand: nutrition and weight cut strategies for mixed martial arts and other combat sports

Following an extensive literature review, the International Society of Sports Nutrition (ISSN) has developed an official position on nutritional and weight cut strategies for combat sports. The type of combat sport, length of the fight camp, and time between weigh-in and competition are factors influencing nutritional and weight cut strategies. The following 16 points constitute the Position Statement of the Society; the Research Committee has approved them. 1. Combat sports have differing weight categories, official weigh-in times, and competition frequencies, influencing the nutritional and weight cut strategies for training and competition. 2. As the duration of a combat match increases, >4 min, contribution of the aerobic system can rise to >70%, yet anaerobic alactic pathways and anaerobic glycolytic pathways support high-output bursts. 3. During the off camp/general preparation phase, athletes should maintain a weight ranging 12% to 15% above the weight division requirement. 4. Supplements including creatine, beta-alanine, beta-hydroxy-beta-methylbutyrate, and caffeine have been shown to enhance performance and/or recovery during preparation phases, competition, and post-competition. 5. During fight camp, strategic decreases in calorie intake are necessary for an efficient longitudinal weight descent. Individual caloric needs can be determined using indirect calorimetry or validated equations such as Mifflin St. Jeor or Cunningham. 6. Protein should be prioritized during longitudinal weight descents to preserve lean body mass, and the timely delivery of carbohydrates supports training demands. Macronutrients should not drop below the following: carbohydrates 3.0-4.0 g/kg, protein 1.2-2.0 g/kg, and fat 0.5 to 1.0 g/kg/day. 7. Suitable losses in body mass range from 6.7% at 72 h, 5.7% at 48 h, and 4.4% at 24 h, prior to weigh-in. 8. Sodium restriction and water loading are effective for inducing polyuria and acute water loss. 9. During fight week, water-bound glycogen stores can be depleted through exercise and carbohydrate restriction, facilitating a 1% to 2% loss in body mass, with equivalent losses from a low-fiber intake of <10 g/day for 4 days. 10. During fight week, acute water loss strategies, including sauna, hot water immersion, and mummy wraps, can be used effectively with appropriate supervision (optimally ~2-4% of body mass within 24 h of weigh-in). 11. Post-weigh-in, rapid weight gain strategies are utilized to recover lost body fluid/mass before competition with the intent of gaining a competitive advantage. 12. Oral rehydration solutions (1 to 1.5 liters/h) combined with a sodium range of 50-90 mmol/dL should take precedence immediately post-weigh-in. 13. Fast-acting carbohydrates at a tolerable rate of ≤ 60 g/h should follow oral rehydration solutions. Post weigh-in intake of fiber should be limited to avoid gastrointestinal distress. 14. Post-weigh-in carbohydrate intake at 8-12 g/kg may be appropriate for combat athletes that undertook significant glycogen depletion strategies during fight week. About 4-7 g/kg may be suitable for modest carbohydrate restriction. 15. Post weigh-in, rehydration/refueling protocols should aim to regain ≥10% of body mass to mitigate declines in performance and the negative effects of rapid weight loss. 16. The long-term effects of frequent weight cuts on health and performance are unknown, necessitating further research.

The Effect of Acute Dehydration upon Muscle Strength Indices at Elite Karate Athletes: A Randomized Crossover Study

Background/Objectives: Acute dehydration, commonly induced through fluid restriction and/or excessive sweating, is a common weight-cutting strategy among combat sport athletes. However, its impact on muscle strength and power remains a concern. The aim of the study was to evaluate the impact of 2% body mass reduction via dehydration on lower-limb strength and power in elite karate athletes. Methods: Fourteen male elite karate athletes completed two conditions: euhydrated (EUH) and dehydrated (DEH) (-2% body mass via 24-h fluid restriction). Performance was assessed using squat jump (SJ) and countermovement jump (CMJ) tests, along with isokinetic knee flexion and extension at 60, 180, and 300°/s. Results: Dehydration significantly reduced squat jump height (37.19 ± 3.69 vs. 39.34 ± 5.08 cm (EUH), p = 0.04), power output (2188.2 ± 307.2 vs. 2351.1 ± 347.2 W (EUH), p = 0.001), and knee extension and flexion strength at 60°/s (p = 0.018). CMJ height and higher-velocity knee flexion/extension were unaffected (p > 0.05). Conclusions: Acute dehydration impairs lower-body maximal force production at low velocities but has no significant effect on high velocity movements. Athletes and coaches should carefully manage hydration strategies when "cutting weight" to avoid any negative performance effects.

Rapid Weight Loss Across Combat Sports and the Relationships Between Methods and Magnitude

This study examined rapid weight loss (RWL) habits across combat sports (CS) and how common usage of different methods was related to the magnitude of RWL. Competitors (N = 256) from CS including boxing, Brazilian jiu-jitsu, muay thai/kickboxing (MT/KB), wrestling, mixed martial arts (MMA), judo, taekwondo, and karate participated in the study. Athletes completed an online survey which included questions on their regular weight loss habits, including magnitudes of weight loss over different time periods and types of methods utilised. Athletes typically started losing weight in their early 20s and engaged in RWL on average three times a year. Magnitudes of weight loss were greater in MT/KB and MMA than other cCS examined (d between 0.63 and 1.54). Wrestlers demonstrated higher prevalence of skipping meals or fasting than other CS (d between 0.7 and 1.29). Athletes at higher competitive levels engaged in larger magnitudes of RWL (d between 0.49 and 0.57). The usage of methods of body fluid manipulation such as fluid restriction, water loading, and sauna were associated with greater amounts of weight loss within 2 weeks and 24 h of weighing in (d between 0.36 and 0.45). Findings indicate that larger weight cuts are linked to strategies involving higher risk, such as sauna, and may be more common among athletes who begin RWL practices at a younger age. Use of certain high-risk methods were associated with increased likelihood of disordered eating behaviours. To reduce reliance on these practices, practitioners and regulators should emphasise the use of smaller weight cuts and to begin losing weight further out from competition.

Appetite-Control and Eating-Behavior Traits Might Not Be Impacted by a Single Weight-Cycling Episode in Weight-Cycling Athletes: Results of the Wave Study

PURPOSE

The impact of weight cycling (WC)-successive weight loss (WL) and weight regain (WG)-on athlete performance is well documented, but effects on appetite are not. This study assessed the impact of a WC episode on dietary and appetitive profiles in athletes, considering sex and sport type.

METHODS

Athletes (28 male, 20 female) from combat (n = 23), strength (n = 12), and endurance (n = 13) sports participated in 3 conditions during a WC episode (baseline, WL, WG). Measurements included body composition (dual-energy X-ray absorptiometry), energy intake (48-h food record), appetite (visual analog scale), dietary profile (questionnaires), and food reward (computer task).

RESULTS

Overall, athletes lost 4.4% (2.3%) of their body weight and regained 4.5% (2.9%) (P < .001). Energy intake decreased during WL (P < .001) with a higher protein intake (% of energy intake) before returning to baseline in WG (P > .05). WL increased hunger, prospective food consumption, and desire to eat compared with the baseline condition, but these changes were not seen in WG. Liking and wanting for fat and sweet foods were higher during WL and remained elevated in WG (P < .05). No eating disorders were found during the WC episode, but combat-sport athletes and females had a higher binge-eating risk than others, independent of the condition.

CONCLUSIONS

Moderate WC episodes do not seem to impair appetite responses in athletes experienced with WC, likely due to their maintaining high physical activity levels. However, their long-term eating-behavior traits, especially in combat and female athletes, seem negatively affected. Practitioners should consider the long-term impacts of these WC practices on nutritional health.

Rapid weight loss and combat athletes: a study on psychological resilience and mechanical hyperalgesia

Introduction

The study investigates the effects of Rapid Weight Loss (RWL) on the levels of psychological resilience and mechanical pain sensitivity in elite kickboxers. The primary aim was to examine changes in psychological resilience subdimensions and pressure pain threshold (PPT) values in the thoracolumbar region before and after a one-month RWL period leading up to competition. Hypotheses included expectations of significant reductions in PPT values due to biomechanical and physiological changes during RWL, along with improvements in psychological resilience subdimensions due to structured routines and social support.

Methods

Thirty-seven elite male athletes (age: 22.94 ± 1.98) participated in the study. Psychological resilience was assessed using the Psychological Resilience Scale for Adults, and mechanical pain sensitivity was evaluated through Pressure Pain Threshold (PPT) measurements. Measurements were conducted before and after the RWL period, spanning one month prior to competition.

Results

The results revealed significant PPT values across all thoracolumbar segments after RWL (p < 0.001). Cohen's d values indicated large effect sizes for these changes (d = 2.10-2.36). The L5 segment exhibited the largest PPT decrease (t = -10.45, d = 2.36), while the Th1 segment showed the smallest decrease (t = -8.23, d = 2.10). Measurements taken at 4 cm from the spine midline also demonstrated significant PPT reductions (p < 0.001), with the highest change recorded in the L5 segment (t = -9.78, d = 2.30). Psychological resilience subdimensions, including "structured style," "social competence," "future orientation," and "social resources," improved significantly after RWL (p < 0.05), while "family cohesion" and "personal strength" did not show significant changes. Athletes who previously ranked in tournaments exhibited higher psychological resilience, potentially due to enhanced self-confidence.

Discussion

These findings align with literature suggesting that competitive success and optimism play crucial roles in resilience development. Personality traits and perceived social support further contributed to the observed resilience levels. This study highlights the multidimensional impact of RWL, emphasizing its detrimental effects on pain sensitivity and its mixed outcomes on psychological resilience. RWL-associated increases in mechanical hyperalgesia, especially in the lumbar region, were attributed to biomechanical and neurophysiological factors. Enhanced psychological resilience observed in certain subdimensions underscores the importance of structured and social support systems in mitigating RWL-induced stress. Future research should explore interventions to optimize resilience and manage pain during RWL periods, focusing on individualized support strategies for athletes. These findings contribute to understanding the interplay between psychological and physiological factors during RWL, practical insights for athletic training.

Getting small to feel big: the psychology of weight cutting in combat sports

This mini review explores the psychological factors associated with weight cutting practices among combat sport athletes. We overviewed combat sport athletes' extrinsic and intrinsic motivations for their sport participation and performance expectations and goals associated with weight cutting. Next, we reviewed the extant research on psychological risk factors associated with weight cutting with a particular focus on combat sport athletes' relationship with food, societal expectations concerning body image, and disordered eating. Finally, we examined how applying task-oriented strategies and Goal Attainment Theory aligns with combat sport athletes' motivation for sport participation. We called for further research into exploring how promoting gradual weight loss may promote psychological resilience with the goal of promoting healthier weight management strategies among combat sport athletes.

The dual impact: physiological and psychological effects of rapid weight loss in wrestling

Introduction

Athletes competing in weight-class sports often seek to gain an advantage by competing at lower weights. Athletes competing in weight-class sports often seek to gain an advantage by competing at lower weights. To achieve this, they aim to lose weight during the competition period, leading to various physiological and psychological changes. This study aimed to investigate the biochemical, hormonal, and psychological effects of weight reduction in elite wrestlers during the competition phase.

Methods

Thirty-seven elite male free style wrestlers (age: 19.02 ± 1.27) participated in the study. Samples were collected 5 days before and on the day of the match.

Results

A significant decrease in body weight was observed (p < 0.05). Levels of creatine, BUN, sodium, hematocrit, hemoglobin, LDH, and cortisol increased, while albumin, testosterone, and FSH levels decreased. There were no significant differences in potassium, ALT, AST, TSH levels. State and trait anxiety scores of the wrestlers increased significantly during the RWL period.

Conclusion

The study concluded that elite wrestlers experienced significant changes in physiological and psychological parameters during the competition periods. These findings underscore the importance of careful monitoring of RWL strategies by coaches and athletes to mitigate the adverse effects on nutritional status, psychological well-being, and physical performance.

The type of sport, but not sex, impacts body composition and metabolic response to a complete weight loss-weight regain episode in weight cycling athletes: results from the WAVE study

Athletes may engage in weight cycling-successive episodes of weight loss and weight (re)gain-for performance reasons, but risk metabolic adaptations and regaining more fat that was lost (fat overshoot). This study aimed to assess the influence of a complete weight cycling episode on body composition, thermoregulation, and metabolism in athletes, considering sex and the type of sport practiced. Forty-eight athletes (28 males, 20 females) engaged in combat (n = 23), strength (n = 12), or endurance (n = 13) sports were examined under three experimental conditions (weight maintenance, weight loss, weight (re)gain) during a weight cycling episode using their habitual strategies. Body composition (dual-energy X-ray absorptiometry), core body temperature (telemetric temperature sensor), energy expenditure and substrate oxidation at rest and during moderate exercise (indirect calorimetry), and energy intake (48 h food record) were assessed. Overall, athletes lost 4.4 ± 2.3% body weight, 12.2 ± 10.6% fat mass, and 2.6 ± 2.3% fat-free mass (p < 0.001). All variables returned to baseline values during the regain period, and a higher fat mass regain was observed in endurance than combat athletes (p < 0.01). During weight loss, a transient increase in lipid and decrease in carbohydrate oxidation occurred at rest and during exercise (p < 0.001). Energy expenditure and core body temperature remained unchanged across the three experimental conditions, and no specific sex effect was observed. Overall, no apparent body weight nor fat overshoot was observed in athletes after a complete weight cycling episode. Nonetheless, the greater fat mass gain in endurance, compared with combat athletes, highlights a need for further specific long-term studies in this population. Clinical Trial registration: NCT04107545.

An analysis of perceptions and thoughts of rapid weight loss in Olympic weightlifters

BACKGROUND

Weight-class athletes commonly engage in rapid weight loss (RWL) practices.

AIM

Investigate attributed RWL perceptions and thoughts of UK-based Olympic weightlifters.

METHODS

Participants (n: 39, male: 22, female: 17) were selected from International Weightlifting Federation populations, 85% had previously acutely reduced pre-competition body mass. The 'Pre-competition weight management practices questionnaire' featured open-ended questions concerning feelings, mood and thoughts during RWL. Qualitative responses were subsequently analysed using content analysis principles.

RESULTS

Negative thoughts and perceptions were commonly attributed concerning RWL, of which codes: irritation, hunger, fatigue, anxiety and low mood accounted for 72% of the 72 data extracts. Females more frequently attributed codes of anxiety, hunger and low mood.

CONCLUSION

The prevalence of negative thoughts and perceptions of RWL accord to previous reports within strength-sport athletes. Olympic weightlifting athletes and coaches should contemplate if negative feelings/mood perceived during RWL are a tolerable factor within pre-event preparation to compete in a desired weight class.

Rapid Weight Changes and Competitive Outcomes in Muay Thai and Mixed Martial Arts: A 14-Month Study of 24 Combat Sports Events

This study investigates the rapid weight loss (RWL) and rapid weight gain (RWG) of contest winners and losers from Muay Thai (MT) and mixed martial arts (MMA) events. The relationship between rapid weight change variables of males and females, and competitive success is also examined. Data from a weight management questionnaire was collected one day post-competition from 185 participants across 24 fight events, resulting in 263 responses (MMA: n = 78, MT: n = 185). Official and secondary weigh-in data were provided by the Combat Sports Commission. The results show that in MT, contest winners compared to losers had significantly greater RWL-7 days (5.9 ± 2.6% vs. 4.6 ± 2.7%, p = 0.01), RWG (6.2 ± 2.9% vs. 4.7 ± 2.8%, p = 0.003), and RWG/RWL ratio (108% [86-132%] vs. 86% [60-119%], p = 0.038), while no significant differences were observed for MMA. Mixed logistic regression models that controlled for age showed that a 1% increase in female RWL-24 h ([OR = 1.57, R2 = 0.105, p = 0.001]) was associated with a 1.6 times higher likelihood of winning compared to female athletes without this increase. We emphasise that associations do not imply causation, and it is possible that other factors which align with rapid weight change practices may impact the observed relationship. Nonetheless, MT contest winners show greater RWL, RWG, and RWG/RWL ratio than losers, and female rapid weight changes appear to be associated with competitive success in this cohort.

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

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.

Energy System Contributions during Olympic Combat Sports: A Narrative Review

This narrative review focuses on the studies that estimate the energy systems' contributions during match simulations of striking (boxing, karate, and taekwondo), grappling (judo), and weapon-based (fencing) Olympic combat sports. The purpose is to provide insights into the metabolism of these athletes. In striking Olympic combat sports, the oxidative contribution varied from 62% (in karate and taekwondo) to 86% (in boxing), the ATP-PCr system contribution varied from 10% (in boxing) to 31% (in taekwondo), and the glycolytic contribution was between 3% (in the third round of taekwondo) and 21% (in karate). In grappling combat sports, only judo was studied, and for a 4 min match, the oxidative contribution was 79%, followed by 14% ATP-PCr system contribution and 7% contribution from the glycolytic system. In fencing, the only weapon-based Olympic combat sport, the oxidative contribution varied from 81% (in the first bout) to 90% (in the second bout), followed by 9% (bout 2) to 12% (bout 1) contribution from the ATP-PCr system, and 0.6% to 7% contribution from the glycolytic system during 3 × 3 min bouts of épée match simulation. Hence, Olympic combat sports are primarily powered by the oxidative system, but the key scoring actions are likely fueled by anaerobic pathways.

Weight Loss and Competition Weight in Ultimate Fighting Championship (UFC) Athletes

Previous research has demonstrated that professional mixed martial arts (MMA) athletes employ a variety of weight manipulation strategies to compete at given weight classes. Although there is much literature demonstrating weight manipulation methods, minimal research exists analyzing how much weight MMA athletes lose prior to the official weigh-in. Moreover, there is minimal research examining how much weight professional MMA athletes gain between the official weigh-in and competition. Therefore, the purpose of the current study was to analyze weight loss/regain in professional MMA athletes. Data collected from 616 professional MMA athletes (31.1 ± 4.0 yrs.; 177.1 ± 4.7 cm) competing for the Ultimate Fighting Championship (UFC) between 2020 and 2022 were used for the study. The athlete's weight was obtained 72 h, 48 h, and 24 h prior to the official weigh-in, at the official weigh-in, and prior to competition. Random effects analysis was utilized to compare weight at a variety of time points between different weight classes. All statistics were analyzed, and significance was set at p ≤ 0.05. There is a significant (p ≤ 0.05) difference between weight classes and time points in professional MMA. MMA athletes decrease body weight significantly prior to the official weigh-in. MMA athletes increase body weight significantly between official weigh-in and competition. Based on these data, it appears that MMA athletes average a weight loss of nearly 7% within 72 h prior to the official weigh-in. The data also suggest that athletes gain nearly 10% of total weight between the official weigh-in and competition.