Food Restriction, Performance, Biochemical, Psychological, and Endocrine Changes in Judo Athletes

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

The aim of this systematic review is to comprehensively assess the weight loss (WL) practices in different combat sports (CS). The review protocol was preregistered with PROSPERO [CRD42023487196]. Three databases were searched (Web of Science, EBSCOhost, and PubMed) until 8 December 2023. Eligible studies had to meet five criteria: they must have been (a) written in English, (b) published in a peer-reviewed journal, (c) used a survey design to investigate the WL practices of CS athletes, and (d) reported the WL methods used by athletes using a five-point scale. Twenty-six studies (3994 participants from 14 CS) were included. This review found that (1) WL is highly prevalent in CS athletes; (2) many CS athletes started losing weight for competition as teenagers two to three times a year; (3) CS athletes usually lose <5% body weight in 7-14 days before competition; (4) increasing exercise and gradually dieting are the most commonly used WL methods; and (5) the influence of scientific practitioners on athletes is negligible. The habitual practices of CS athletes may be relatively harmless, but in some special cases, CS athletes also perform extreme WL practices. Scientific practitioners have little influence on their WL practices, which may form a vicious cycle of non-qualified influence.

Physiological Perturbations in Combat Sports: Weight Cycling and Metabolic Function-A Narrative Review

Combat sports athletes seeking a competitive edge often engage in weight management practices to become larger than their opponents, which ultimately includes periods of gradual weight loss, rapid weight loss, and weight regain. This pattern of weight loss and regain is known as weight cycling and often includes periods of low energy availability, making combat sports athletes susceptible to metabolic dysfunction. This narrative review represents an effort to explore the metabolic perturbations associated with weight cycling and outline the short-, medium-, and long-term effects on metabolic flexibility, function, and health. The short-term effects of rapid weight loss, such as a reduced metabolic rate and alterations to insulin and leptin levels, may prelude the more pronounced metabolic disturbances that occur during weight regain, such as insulin resistance. Although definitive support is not currently available, this cycle of weight loss and regain and associated metabolic changes may contribute to metabolic syndrome or other metabolic dysfunctions over time.

Prevalence of metabolic syndrome and its association with rapid weight loss among former elite combat sports athletes in Serbia

BACKGROUND

In terms of the potential influence of rapid weight loss (RWL) on the metabolic health of former combat sports athletes (CSA), the scientific literature is quite scarce. Therefore, the objective of the presented research was to determine the differences in metabolic syndrome (MetS) parameters and the prevalence of MetS between former athletes who performed RWL and athletes who did not.

METHODS

The sample of the presented study comprised 150 participants from Serbia, equally divided into two groups: 75 former athletes who had practiced combat sports and 75 ex-athletes of various other sports who did not practice RWL during their careers. The following parameters related to the MetS were evaluated: waist circumference, high-density lipoprotein cholesterol, systolic blood pressure, diastolic blood pressure, fasting glucose, and triglycerides. The oral glucose tolerance test (OGTT) was used to assess the participant's body response to sugar.

RESULTS

The RWL group had significantly higher both systolic (p < 0.001) and diastolic blood pressure (p < 0.001) compared to the group of athletes who did not practice weight reduction during their careers. Additionally, a tendency toward statistically significant differences between groups was recorded in the variable triglycerides (p = 0.069). Regarding OGTT, increased values of fasting blood glucose at the final measurement were revealed only in the RWL group (p = 0.003). The prevalence of MetS was substantially higher in CSA than in the control group (39.5% vs. 16.2%, respectively p = 0.002).

CONCLUSIONS

This study suggests that former elite CSA who used RWL during their sports career are susceptible to negative metabolic alterations at the end of their competitive period.

Beta-hydroxy-beta-methylbutyrate supplementation preserves fat-free mass in collegiate boxers during acute body mass loss

Acute body mass loss before competitions in combat sports usually leads to loss in fat-free mass. Beta-hydroxy-beta-methylbutyrate (HMB) has been shown to increase skeletal muscle mass and muscle strength in various muscle wasting conditions. This study investigated the effect of HMB supplementation on body composition and sport-specific performance in well-trained boxers consuming a hypocaloric diet. Twelve male college boxers were divided into the HMB and placebo (PLA) groups using a body weight-matched single-blind parallel design. The study comprised a 6-day weight loss period (days 1-6), followed by a 3-day competition period (days 7-9). The participants in both the groups consumed 16 kcal/kg/day, including 1.6-1.7 g/kg of carbohydrates, 1.2-1.3 g/kg of protein, and 0.45-0.5 g/kg of fat during the 9-day period. The HMB group consumed 3 g/day HMB. Body composition measurement, isometric mid-thigh pull (IMTP), and a simulated boxing match were performed at baseline and on days 7, 8, and 9. Fasting blood samples were collected on the day before day 1 and on days 7, 8, and 9. Body mass was significantly decreased after the 6-day weight loss period (HMB group: baseline: 69.4 ± 11.2 kg, day 7: 67.1 ± 11.2 kg; PLA group: baseline: 68.6 ± 12.1 kg, day 7: 65.7 ± 11.5 kg, P < 0.05) while it was unchanged on the 3-day competition period in both the groups. Fat-free mass in the HMB group was maintained throughout the 9-day period (baseline: 56.7 ± 9.3 kg, day 7: 56.3 ± 8.7 kg, day 9: 55.8 ± 9.5 kg) whereas it significantly decreased on days 7 and 9 compared to the baseline in the PLA group (baseline: 55.2 ± 6.4 kg, day 7: 54.1 ± 6.6 kg, day 9: 54.0 ± 6.6 kg, P < 0.05). In the PLA group, the average and maximal heart rates in round 1 and the average heart rate in round 2 on days 8 and 9 were significantly lower than those at baseline, while these parameters were unchanged in the HMB group. The maximal force and the rate of force development in the IMTP remained unchanged among the different timepoints in both the groups. The blood biochemical parameters were similar at any timepoint between the PLA and HMB groups. HMB supplementation during acute weight loss may preserve fat-free mass and maintain heart rate response in subsequent simulated matches in well-trained boxers. In addition, HMB supplementation had a nonsignificant effect on glucose, fat, and protein metabolism during energy restriction.

Low- or moderate-carbohydrate calorie-restricted diets have similar effects on body composition and taekwondo performance after high-carbohydrate recovery meals

Low-carbohydrate (LC) diets are popular among general and athletic populations attempting to lose body mass. This study investigated the effect of a 7-day LC or moderate-carbohydrate (MC) calorie-restricted diet followed by 18-h recovery on body composition and taekwondo-specific performance. In this randomised cross-over study, 12 male taekwondo athletes consumed an LC (10% of carbohydrate, 41% of protein, 49% of fat, and 15.8 ± 0.4 kcal/kg/day) or an isocaloric MC diet (60% of carbohydrate, 30% of protein, and 10% of fat) for 7 days. The participants then consumed a carbohydrate-rich recovery dinner (39.2 ± 3.1 kcal/kg) followed by breakfast (6.2 ± 0.4 kcal/kg) in both the trials. Three repeated sprint ability (RSA) tests were conducted after breakfast. The taekwondo-specific reaction battery was administered before the first RSA test and after each RSA test. The participants experienced similar magnitudes of significant loss of body mass in the LC (-2.4 ± 1.7%) and MC (-2.3 ± 1.7%) trials. Fat mass and fat percentage significantly decreased in the MC trial but remained unchanged in the LC trial after body mass loss. Fat free mass was maintained in both the trials. The average and peak power in the RSA tests and the premotor reaction time were similar between the trials. The participants experienced significantly higher fatigue in the LC trial. In conclusion, both the diets can help athletes rapidly lose body mass while maintaining performance as long as an adequate amount of carbohydrate is consumed during the recovery period.

Examining the effects of pre-competition rapid weight loss on hydration status and competition performance in elite judo athletes

The prevalence of rapid weight loss (RWL) among martial arts athletes including judo is very high. Many applied RWL strategies could be dangerous to health and even lead to death. Therefore, the International Judo Federation (IJF) introduced changes in the weigh-in rules, changing the official weigh-in for the day before the competition. Thus, the purpose of this study was to examine the impact of the new IJF rules on hydration status and weight loss strategies among professional judo athletes. Seventeen elite judo athletes participated in the study. Body mass and hydration status, were analyzed before the competition. Moreover, competition result and practice of RWL survey were collected. All subjects reached their weight category limits for the competition. RWL resulted in body mass changes (p < 0.001, ηp2 = 0.79) and dehydration among participants (urine osmolality > 700 [mOsmol*kg]-1 and urine specific gravity > 1.020 [g*cm3]-1). However, urine osmolality (p > 0.05, ηp2 = 0.18), as well as urine specific gravity (p > 0.05, ηp2 = 0.16), at subsequent time points of measurement revealed no statistical differences. The prevalence of RWL was 100%, and only 17.6% of the athletes declared that they would compete in a different weight category if the competition would be conducted on the same day of the weigh-in. All judo athletes applied RWL procedures using traditional methods to achieve the required body mass (i.e., increased exercise, reduced fluid, and food intake). Dehydration state was not associated with competitive performance (p > 0.05).

2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs)

Relative Energy Deficiency in Sport (REDs) was first introduced in 2014 by the International Olympic Committee's expert writing panel, identifying a syndrome of deleterious health and performance outcomes experienced by female and male athletes exposed to low energy availability (LEA; inadequate energy intake in relation to exercise energy expenditure). Since the 2018 REDs consensus, there have been >170 original research publications advancing the field of REDs science, including emerging data demonstrating the growing role of low carbohydrate availability, further evidence of the interplay between mental health and REDs and more data elucidating the impact of LEA in males. Our knowledge of REDs signs and symptoms has resulted in updated Health and Performance Conceptual Models and the development of a novel Physiological Model. This Physiological Model is designed to demonstrate the complexity of either problematic or adaptable LEA exposure, coupled with individual moderating factors, leading to changes in health and performance outcomes. Guidelines for safe and effective body composition assessment to help prevent REDs are also outlined. A new REDs Clinical Assessment Tool-Version 2 is introduced to facilitate the detection and clinical diagnosis of REDs based on accumulated severity and risk stratification, with associated training and competition recommendations. Prevention and treatment principles of REDs are presented to encourage best practices for sports organisations and clinicians. Finally, methodological best practices for REDs research are outlined to stimulate future high-quality research to address important knowledge gaps.

Prevalence and risk factors of poor subjective sleep quality in elite judo athletes

This study aimed to determine the prevalence and risk factors of poor subjective sleep quality in elite judo athletes. A subjective cross-sectional questionnaire survey was conducted with 106 elite judo athletes who participated in the training camp of the Japanese national team. Eighty-six respondents (men: 52.3%; average age: 22.9 ± 3.1 years) with complete responses were included in the analysis (valid response rate: 81.1%). Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). The prevalence of poor sleep quality (PSQI score ≥ 5.5), the mean PSQI score, and subscale scores were investigated. Relationships between poor sleep quality and attributes, lifestyle habits, competition-based activities, and psychological distress were explored using Fisher's exact tests and multivariate logistic regression analysis. Thirty-five respondents (40.7%) reported poor sleep quality. The percentage and subscale scores of the respondents for sleep latency, sleep duration, and daytime dysfunction were higher than those of the population of Japanese national-level athletes. The mean PSQI score of the respondents was similar to that of some elite athlete populations but higher than those of others. Multivariate logistic regression analysis revealed that psychological distress was associated with poor sleep quality. In conclusion, the prevalence of poor subjective sleep quality in elite judo athletes was suggested to be similar or higher among elite athlete population. Sleep latency, sleep duration, and daytime dysfunction status were worse in elite judo athletes than in Japanese national-level athletes. Psychological distress was a risk factor for poor subjective sleep quality in elite judo athletes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00444-6.

Rapid weight loss can increase the risk of acute kidney injury in wrestlers

Objective

Restrictive diets, forced starvation or voluntary weight loss are attracting more and more attention from scientists. Overall trends show that about 80% of combat sports athletes use specific methods of reducing body mass. Rapid weight loss could be a risk factor for kidney-related adverse outcomes. This study aimed to examine the impact of high-intensity specific training combined with rapid weight loss in the first and without rapid weight loss in the second phases on body composition and biochemical markers of kidney function.

Methods

The study was conducted on 12 male wrestlers. Kidney function markers were measured, including blood urea nitrogen, serum creatinine, uric acid and serum Cystatin-C. Alterations in analysed markers were noted in both phases of the research.

Results

According to the data, a significant increase was noted in blood urea nitrogen (p=0.002), uric acid (p=0.000) and serum creatinine (p=0.006) during the first phase in comparison with the second phase. The levels of serum Cystatin-C were slightly elevated after both phases compared with the initial measurement.

Conclusion

It is evident that high-intensity specific training combined with rapid weight loss significantly affects the increase in kidney function markers compared with identical training without rapid weight loss. The findings in this study suggest that rapid body mass reduction is associated with an increased risk of acute kidney injury in wrestlers.

Lightest weight-class athletes are at higher risk of weight regain: results from the French-Rapid Weight Loss Questionnaire

CONTEXT

Rapid weight loss (RWL) is a common precompetitive strategy used by athletes in weight-class sports and carries with it an increased risk to future cardiometabolic health. The Rapid Weight Loss Questionnaire (RWLQ) is a self-reported tool designed to identify and characterize such weight loss practices.

OBJECTIVES

After developing a reliable and reproducible French version of the RWLQ (RWLQ-FR), the present study aims to analyse RWL patterns among French weight-class athletes and to point out potential relationships between such practices and risk of subsequent weight gain.

METHODS

A test-retest analysis was performed in 54 athletes to test the questionnaire reproducibility before applying it in a cohort of 168 weight-cycling athletes (23.78 ± 9.25 y, 67.6 ± 12.6 kg, 81 males and 87 females, n = 24 strength sports and n = 144 various combat sports).

RESULTS

The test-retest showed good agreement of the RWLQ-FR (Rho = 0.794, [0.696-0.893]). Athletes reported losing an average of 4.1 ± 2.9% of their initial weight in 13.1 ± 9.6 days, with the main methods used being an increase in exercise, training in rubber or plastic suits, and gradual dieting. The average weight recovery in a week was 3.5 ± 2.8% and results showed that the athletes with the lower inter-season weight (weight outside of the training and competition season) regained the more weight (p = 0.025). The average RWLQ-FR score was 31.9 ± 17.3 and athletes who began to lose weight earlier in their competitive carrier had the higher scores (p = 0.032).

CONCLUSION

The present study demonstrates relationships between the pattern of RWL practices and potential increased risk of subsequent weight gain in weight-cycling athletes, and the need to better understand the long-term health-related risks.

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.

Training Conditions and Psychological Health: Eating Behavior Disorders in Spanish High-Performance Women's Olympic Wrestling Athletes-A Qualitative Study

(1) Background: the aim of this study was to determine the factors that affect the occurrence of behaviors related to possible eating disorders in Spanish high-performance Olympic wrestling athletes. (2) Methods: The sample consisted of 22 elite female wrestlers selected through purposive sampling with inclusion criteria of (i) having been a national champion, (ii) having been part of the Spanish team, and (iii) suffering or having suffered from an eating disorder. The semistructured interviews were conducted online and lasted between 20 and 40 min. A statistical analysis was performed with NVivo10 software. (3) Results: the athletes showed a series of issues grouped into three main themes, which were divided into the following categories-firstly, the reasons why wrestlers lose weight; secondly, the inadequate procedures they use; and, finally, the reference persons involved in the process. (4) Conclusions: The training conditions in high-performance sports have psychological and behavioral effects on wrestlers. Wrestlers have to move down to lower categories; however, they do not take into account how this practice influences their health when using inadequate procedures. Rapid and significant weight loss produces negative effects, especially in the female population, generating an incidence of eating disorders. The information obtained provided elements of interest for reflection on possible solutions to prevent existing eating disorders.

Effect of rapid weight loss on mood states and burnout of Brazilian jiu-jitsu athletes during a competitive process

The current study aimed to analyze the psychological alterations resulting from rapid weight loss in the mood states and burnout of male Brazilian jiu-jitsu athletes. For the purpose of this study, 31 Brazilian jiu-jitsu athletes participated, divided into two groups (RWLG: rapid weight loss group and CG: control group). Data collections were performed at three moments (1: baseline, before weight loss; 2: weigh-in, during the official competition; and 3: recovery, 7 to 10 days after the competition), with application of the Brunel Mood Scale (BRUMS) and Athlete Burnout Questionnaire (ABQ). Considering the outcomes, for body mass, the athletes from RWLG presented mean reductions of 3.5 kg (4.2% of the initial body mass). For mood states, both groups (RWLG and CG) presented a moment effect for tension and confusion, with higher levels during weigh-in compared to baseline and recovery (p < 0.05). For burnout, both groups showed low levels of burnout, with no effect of moment, group, or interaction in the analyses (p > 0.05). Based on these results, it is concluded that weight loss, in the magnitude performed in this study, did not generate an additional impact on mood or level of burnout in Brazilian jiu-jitsu athletes during a competitive process.

Rapid weight loss among elite-level judo athletes: methods and nutrition in relation to competition performance

Background

Methods

Results

Conclusions

Effect of Time-Restricted Feeding on Anthropometric, Metabolic, and Fitness Parameters: A Systematic Review

Time restricted feeding (TRF) as a form of intermittent fasting (IF) has gained popularity because its ability to reduce body mass (BM) without an emphasis on caloric restriction. However, how this dietary protocol may affect health, fitness, and performance in a relatively healthy cohort remains less clear. The purpose of this article was to systematically review the current literature concerning the effect of TRF on anthropometric, metabolic, and fitness parameters in normal-weight adults and overweight and obese individuals. A systematic search of English literature was conducted through databases including PubMed, CINAHL, and Google Scholar. The search was facilitated by using various combinations of key words related to nutritional interventions, i.e., IF and TRF, and outcomes of interest, i.e., BM, body composition, glucose, insulin, lipid, fitness, and performance. The article selection was made based on the inclusion and exclusion criteria concerning the participants' characteristics, study design, intervention protocols, and targeted dependent variables. Twenty-three full-text longitudinal randomized and nonrandomized controlled studies were selected for this review. Our analysis indicates that TRF can reduce BM and improve nutrient metabolism in both normal- and over-weight individuals. TRF does not appear to alter protein synthesis and fat-free mass nor hamper aerobic fitness and muscular performance among physically active individuals including athletes. In conclusion, TRF as a more easily adaptable form of IF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function. However, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power.Key teaching points and nutritional relevanceTime-restricted feeding (TRF) differs from other fasting protocols due to its emphasis on restricting eating window rather than caloric intake and can be more easily adopted by simply skipping a meal.Its deemphasis on caloric restriction appeals to many young and physically active individuals wanting to optimize body composition but needing sufficient energy to support their physical training and daily activity.Much of what is known regarding the impact of TRF on fitness and athletic performance was derived from studies that use the Ramadan fasting protocol, which differs from TRF in terms of protocol duration and feeding schedule.This review concludes that TRF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function in both normal- and over-weight individuals.Due to limited evidence concerning TRF and athletic performance, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power.

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

Weight cutting in combat sports is a prevalent practice whereby athletes voluntarily dehydrate themselves via various methods to induce rapid weight loss (RWL) to qualify for a lower weight category than that of their usual training body weight. The intention behind this practice is to regain the lost body mass and compete at a heavier mass than permitted by the designated weight category. The purpose of this study was to quantitatively synthesize the available evidence examining the effects of weight cutting on exercise performance in combat-sport athletes. Following a systematic search of the literature, meta-analyses were performed to compare maximal strength, maximal power, anaerobic capacity, and/or repeated high-intensity-effort performance before rapid weight loss (pre-RWL), immediately following RWL (post-RWL), and 3 to 36 hours after RWL following recovery and rapid weight gain (post-RWG). Overall, exercise performance was unchanged between pre-RWL and post-RWG (g = 0.22; 95% CI, -0.18 to 0.62). Between pre-RWL and post-RWL analyses revealed small reductions in maximal strength and repeated high-intensity-effort performance (g = -0.29; 95% CI, -0.54 to -0.03 and g = -0.37; 95% CI, -0.59 to -0.16, respectively; both P ≤ .03). Qualitative analysis indicates that maximal strength and power remained comparable between post-RWL and post-RWG. These data suggest that weight cutting in combat-sport athletes does not alter short-duration, repeated high-intensity-effort performance; however, there is evidence to suggest that select exercise performance outcomes may decline as a product of RWL. It remains unclear whether these are restored by RWG.

Screening for Low Energy Availability in Male Athletes: Attempted Validation of LEAM-Q

A questionnaire-based screening tool for male athletes at risk of low energy availability (LEA) could facilitate both research and clinical practice. The present options rely on proxies for LEA such screening tools for disordered eating, exercise dependence, or those validated in female athlete populations. in which the female-specific sections are excluded. To overcome these limitations and support progress in understanding LEA in males, centres in Australia, Norway, Denmark, and Sweden collaborated to develop a screening tool (LEAM-Q) based on clinical investigations of elite and sub-elite male athletes from multiple countries and ethnicities, and a variety of endurance and weight-sensitive sports. A bank of questions was developed from previously validated questionnaires and expert opinion on various clinical markers of LEA in athletic or eating disorder populations, dizziness, thermoregulation, gastrointestinal symptoms, injury, illness, wellbeing, recovery, sleep and sex drive. The validation process covered reliability, content validity, a multivariate analysis of associations between variable responses and clinical markers, and Receiver Operating Characteristics (ROC) curve analysis of variables, with the inclusion threshold being set at 60% sensitivity. Comparison of the scores of the retained questionnaire variables between subjects classified as cases or controls based on clinical markers of LEA revealed an internal consistency and reliability of 0.71. Scores for sleep and thermoregulation were not associated with any clinical marker and were excluded from any further analysis. Of the remaining variables, dizziness, illness, fatigue, and sex drive had sufficient sensitivity to be retained in the questionnaire, but only low sex drive was able to distinguish between LEA cases and controls and was associated with perturbations in key clinical markers and questionnaire responses. In summary, in this large and international cohort, low sex drive was the most effective self-reported symptom in identifying male athletes requiring further clinical assessment for LEA.

The Association between Rapid Weight Loss and Body Composition in Elite Combat Sports Athletes

Rapid Weight Loss (RWL) is a rapid reduction in weight over a short period of time seeking to attain the norm required for a competition in a particular weight category. RWL has a negative health impact on athletes including the significant muscle damage induced by RWL. This study aimed to identify the association between RWL and body composition among competitive combat athletes (n = 43) in Lithuania. Our focus was laid on the disclosure of their RWL practice by using a previously standardized RWL Questionnaire. The body composition of the athletes was measured by means of the standing-posture 8-12-electrode multi-frequency bioelectrical impedance analysis (BIA) and the electrical signals of 5, 50, 250, 550 and 1000 kHz. This non-experimental cross-sectional study resulted in preliminary findings on the prevalence and profile of RWL among combat athletes in Lithuania. 88% of the athletes surveyed in our study had lost weight in order to compete, with the average weight loss of 4.6 ± 2% of the habitual body mass. The athletes started to resort to weight cycling as early as 9 years old, with a mean age of 12.8 ± 2.1 years. The combination of practiced weight loss techniques such as skipping meals (adjusted Odd Ratio (AOR) 6.3; 95% CI: 1.3−31.8), restricting fluids (AOR 5.5; 95% CI: 1.0−31.8), increased exercise (AOR 3.6; 95% CI: 1.0−12.5), training with rubber/plastic suits (AOR 3.2; 95% CI: 0.9−11.3) predicted the risk of RWL aggressiveness. RWL magnitude potentially played an important role in maintaining the loss of muscle mass in athletes during the preparatory training phase (β −0.01 kg, p < 0.001). Therefore, an adequate regulatory programme should be integrated into the training plans of high-performance combat sports athletes to keep not only the athletes but also their coaches responsible for a proper weight control.

Performance Alteration Induced by Weight Cutting in Mixed Martial Arts-A Biomechanical Pilot Investigation

Currently, there are pros and cons of research results related to weight cutting in combat sports, resulting in inconclusive results regarding the effects of weight-cut on athletes’ performance, and biomechanical investigations are hardly seen. Therefore, this pilot study tried to fill the gap by initiating an exploration in real-life competitions. It is our hope to add biomechanical insights (advantages/disadvantages) that would discern the impact of weight cutting on competitive performance and help to structure hypotheses in future research. The method consisted of 3D motion capture, EMG measurement and biomechanical modeling. Through the synchronized data, striking power, striking accuracy and reaction time were quantitatively determined. Pre- and post-test design was used to test common strikes before weight cutting and 24 h after weigh-in. Seven male athletes from local clubs were tested during regional competitions. Results were characterized by using descriptive statistics (means and standard deviations) and T-tests were performed to contrast differences between the pre- and post-tests. This pilot study has revealed that there is actually weight-regain instead of weight-loss. The weight-regain would speed up the perceptional and total reaction, slow down the limbs’ movement, worsen the striking accuracy and, possibly, decrease the strike power. The preliminary results are inconclusive regarding the competitive advantages/disadvantages induced by weight cutting. Further biomechanical studies are needed to deal with the controversial subject more objectively and scientifically.

Nutritional Considerations for Injury Prevention and Recovery in Combat Sports

Sports participation is not without risk, and most athletes incur at least one injury throughout their careers. Combat sports are popular all around the world, and about one-third of their injuries result in more than 7 days of absence from competition or training. The most frequently injured body regions are the head and neck, followed by the upper and lower limbs, while the most common tissue types injured are superficial tissues and skin, followed by ligaments and joint capsules. Nutrition has significant implications for injury prevention and enhancement of the recovery process due to its effect on the overall physical and psychological well-being of the athlete and improving tissue healing. In particular, amino acid and protein intake, antioxidants, creatine, and omega-3 are given special attention due to their therapeutic roles in preventing muscle loss and anabolic resistance as well as promoting injury healing. The purpose of this review is to present the roles of various nutritional strategies in reducing the risk of injury and improving the treatment and rehabilitation process in combat sports. In this respect, nutritional considerations for muscle, joint, and bone injuries as well as sports-related concussions are presented. The injury risk associated with rapid weight loss is also discussed. Finally, preoperative nutrition and nutritional considerations for returning to a sport after rehabilitation are addressed.

Olympic Sports Science-Bibliometric Analysis of All Summer and Winter Olympic Sports Research

Introduction: The body of scientific literature on sports and exercise continues to expand. The summer and winter Olympic games will be held over a 7-month period in 2021-2022. Objectives: We took this rare opportunity to quantify and analyze the main bibliometric parameters (i.e., the number of articles and citations) across all Olympic sports to weigh and compare their importance and to assess the structure of the "sport sciences" field. The present review aims to perform a bibliometric analysis of Olympic sports research. We quantified the following topics: (1) the most investigated sports; (2) the main journals in which the studies are published; (3) the main factors explaining sport-specific scientific attractiveness; (4) the influence of being in the Olympic programme, economic weight, and local influences on research output; and (5) which research topic is the most investigated across sports. Methods: We searched 116 sport/exercise journals on PubMed for the 40 summer and 10 winter Olympic sports. A total of 34,038 articles were filtered for a final selection of 25,003 articles (23,334 articles on summer sports and 1,669 on winter sports) and a total of 599,820 citations. Results and Discussion: Nine sports [football (soccer), cycling, athletics, swimming, distance & marathon running, basketball, baseball, tennis, and rowing] were involved in 69% of the articles and 75% of the citations. Football was the most cited sport, with 19.7 and 26.3% of the total number of articles and citations, respectively. All sports yielded some scientific output, but 11 sports (biathlon, mountain biking, archery, diving, trampoline, skateboarding, skeleton, modern pentathlon, luge, bobsleigh, and curling) accumulated a total of fewer than 50 publications. While ice hockey is the most prominently represented winter sport in the scientific literature, winter sports overall have produced minor scientific output. Further analyses show a large scientific literature on team sports, particularly American professional sports (i.e., baseball, basketball, and ice hockey) and the importance of inclusion in the Olympic programme to increasing scientific interest in "recent" sports (i.e., triathlon and rugby sevens). We also found local/cultural influence on the occurrence of a sport in a particular "sport sciences" journal. Finally, the relative distribution of six main research topics (i.e., physiology, performance, training and testing, injuries and medicine, biomechanics, and psychology) was large across sports and reflected the specific performance factors of each sport.

Principles of Rapid Weight Loss in Female Sambo Athletes

In combat sports, competitors are separated into weight divisions, to create equality between the athletes. Consequently, rapid weight loss (RWL) is a common practice in combat sports. Although the methods used to induce RWL are similar among athletes, currently, there are limited data concerning the RWL methodologies used by sambo athletes. Therefore, this study aimed at determining RWL procedures among female sambo athletes. Participants in the study were top-level athletes competing at the World Sambo Championship held in Novi Sad. A total sample of 47 female sambo athletes, of whom 24 were seniors (27.3 ± 4 year/age, 1.61 ± 0.09 m/height, 61.8 ± 8.87 kg/weight) and 23 juniors (18.7 ± 0.8 year/age, 1.66 ± 0.07 m/height, 63.7 ± 12.1 kg/weight), were examined in the study. To determine RWL methods, data were collected through a standardized questionnaire. As a result, 88.7% of the female sambo athletes declared that they intentionally cut their weight before the competition. The most commonly used methods were gradual dieting, followed by sauna, fluid restriction, and skipping meals. The most considerable influence on the RWL strategies of athletes came from coaches and personal trainers, while physicians and dietitians were far less influential. The results obtained from this representative sample highlight the most common practices concerning weight cutting prior to competition among females. Therefore, there is a need to inform and educate both athletes and coaches about the potentially harmful effects of RWL in combat sports.

Examining the effects of calorie restriction on testosterone concentrations in men: a systematic review and meta-analysis

CONTEXT

Testosterone concentrations decline with age, and lower testosterone concentrations are associated with several morbidities, including sexual dysfunction, obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome.

OBJECTIVE

Because dietary habits play a critical role in weight regulation and T2DM management, the aim of this systematic review and meta-analysis was to summarize and critically evaluate the evidence from randomized controlled trials to determine the effects of calorie restriction (CR) on testosterone concentrations in men.

DATA SOURCES

A literature search was conducted across 4 databases, from their inception until March 2020.

DATA EXTRACTION

The screening and data extraction were completed by 2 authors independently, and in a blinded manner, according to a priori inclusion and exclusion criteria.

DATA ANALYSIS

Of the 4198 studies identified from the initial search, 7 randomized controlled trials were included for data extraction. Significant increases in total testosterone concentrations were reported in 3 of 4 studies in which CR was examined with overweight or obese men, compared with the control groups. Significant decreases in total testosterone concentrations were reported in 2 of 3 studies in which the effects of CR were examined with normal-weight, healthy men, compared with the control groups. In all 4 studies that examined the effect of CR on sex hormone-binding globulin concentrations, the intervention significantly increased sex hormone-binding globulin concentrations compared with that of the control groups irrespective of body composition.

CONCLUSION

This systematic review and meta-analysis provide some evidence that CR affects testosterone concentrations in men and this effect depends on their body mass index. PROSPERO registration no. CRD42020173102.

Exposure to Normobaric Hypoxia Combined with a Mixed Diet Contributes to Improvement in Lipid Profile in Trained Cyclists

This study aimed to analyze the effects of live high-train low method (LH-TL) and intermittent hypoxic training (IHT) with a controlled mixed diet on lipid profile in cyclists. Thirty trained male cyclists at a national level with at least six years of training experience participated in the study. The LH-TL group was exposed to hypoxia (FiO2 = 16.5%) for 11-12 h a day and trained under normoxia for 3 weeks. In the IHT group, participants followed the IHT routine three times a week under hypoxia (FiO2 = 16.5%) at lactate threshold intensity. The control group (N) lived and trained under normoxia. The results showed that the 3-week LH-TL method significantly improved all lipid profile variables. The LH-TL group showed a significant increase in HDL-C by 9.0% and a decrease in total cholesterol (TC) by 9.2%, LDL-C by 18.2%, and triglycerides (TG) by 27.6%. There were no significant changes in lipid profiles in the IHT and N groups. ∆TG and ∆TC were significantly higher in the LH-TL group compared to the N group. In conclusion, hypoxic conditions combined with a mixed diet can induce beneficial changes in lipid profile even in highly trained athletes. The effectiveness of the hypoxic stimulus is closely related to the hypoxic training method.

Continuous versus Intermittent Dieting for Fat Loss and Fat-Free Mass Retention in Resistance-trained Adults: The ICECAP Trial

INTRODUCTION

Can intermittent energy restriction (IER) improve fat loss and fat-free mass retention compared with continuous energy restriction (CER) in resistance-trained adults?

METHODS

Sixty-one adults (32 women) with a mean (SD) age of 28.7 (6.5) yr, body weight of 77.2 (16.1) kg, and body fat of 25.5% (6.1%) were randomized to 12 wk of 1) 4 × 3 wk of moderate (m) energy restriction interspersed with 3 × 1 wk of energy balance (mIER; n = 30; 15 wk total) or 2) 12 wk of continuous moderate energy restriction (mCER; n = 31). Analyses of all outcome measures were by intention-to-treat.

RESULTS

After accounting for baseline differences, mIER did not result in lower fat mass or body weight, or greater fat-free mass, compared with mCER after energy restriction. Mean (and 97.5% confidence interval for fat mass at the end of mIER versus mCER was 15.3 (12.5-18.0) kg versus 18.0 (14.3-21.7) kg (P = 0.321), that for fat-free mass was 56.7 (51.5-61.9) kg versus 56.7 (51.4-62.0) kg (P = 0.309), and that for body weight (with 95% confidence interval) was 72.1 (66.4-77.9) versus 74.6 (69.3-80.0) (P = 0.283). There were no differences between interventions in muscle strength or endurance or in resting energy expenditure, leptin, testosterone, insulin-like growth factor-1, free 3,3',5-triiodothyronine or active ghrelin, or in sleep, muscle dysmorphia, or eating disorder behaviors. However, participants in mIER exhibited lower hunger (P = 0.002) and desire to eat (P = 0.014) compared with those in mCER, and greater satisfaction (P = 0.016) and peptide YY (P = 0.034).

CONCLUSIONS

Similar fat loss and fat-free mass retention are achieved with mIER and mCER during 12 wk of energy restriction; however, mIER is associated with reduced appetite.

Rapid Weight Loss Practices in Elite Kickboxers

The aim of this observational cross-sectional survey was to determine the prevalence of rapid weight loss (RWL) in elite kickboxers. Kickboxers (61 males; age = 24.2 ± 4.6 years, weight = 73.9 ± 12.8 kg, and height = 179.2 ± 7.9 cm) from eight European countries completed a Rapid Weight Loss Questionnaire regarding prevalence, magnitude, and methods of RWL. All athletes (100%) were practicing RWL before the competition with a Rapid Weight Loss Questionnaire score of 52.4 ±12.9. Most kickboxers 'usually lose between 2% and 5% of their body mass, whereas ∼30% lose between 6% and 8%. However, it is alarming that almost 30% reported cutting 10% of body weight or more sometime during their kickboxing career. Almost half of the athletes always practice gradual dieting (45.9%) and increased exercising (44.3%) to reduce body mass. Kickboxers usually reduce weight three to four times during a year, usually 7-15 days before a competition. More than a third (34.4%) started with RWL practice under the age of 17. There was no significant difference between weight divisions in weight management behaviors (p = .5, F = 0.6; η2 = .0) and no relation between the main characteristics of elite kickboxing athletes and the total RWL score. In conclusion, RWL practices in kickboxing athletes are somewhat specific and different when compared with other combat sports, which can be explained by greater number of weight classes and specific weigh-in protocol.

High-Protein Energy-Restriction: Effects on Body Composition, Contractile Properties, Mood, and Sleep in Active Young College Students

Background: It is often advised to ensure a high-protein intake during energy-restricted diets. However, it is unclear whether a high-protein intake is able to maintain muscle mass and contractility in the absence of resistance training. Materials and Methods: After 1 week of body mass maintenance (45 kcal/kg), 28 male college students not performing resistance training were randomized to either the energy-restricted (ER, 30 kcal/kg, n = 14) or the eucaloric control group (CG, 45 kcal/kg, n = 14) for 6 weeks. Both groups had their protein intake matched at 2.8 g/kg fat-free-mass and continued their habitual training throughout the study. Body composition was assessed weekly using multifrequency bioelectrical impedance analysis. Contractile properties of the m. rectus femoris were examined with Tensiomyography and MyotonPRO at weeks 1, 3, and 5 along with sleep (PSQI) and mood (POMS). Results: The ER group revealed greater reductions in body mass (Δ -3.22 kg vs. Δ 1.90 kg, p < 0.001, partial η ² = 0.360), lean body mass (Δ -1.49 kg vs. Δ 0.68 kg, p < 0.001, partial η ² = 0.152), body cell mass (Δ -0.85 kg vs. Δ 0.59 kg, p < 0.001, partial η ² = 0.181), intracellular water (Δ -0.58 l vs. Δ 0.55 l, p < 0.001, partial η ² = 0.445) and body fat percentage (Δ -1.74% vs. Δ 1.22%, p < 0.001, partial η ² = 433) compared to the CG. Contractile properties, sleep onset, sleep duration as well as depression, fatigue and hostility did not change (p > 0.05). The PSQI score (Δ -1.43 vs. Δ -0.64, p = 0.006, partial η ² = 0.176) and vigor (Δ -2.79 vs. Δ -4.71, p = 0.040, partial η ² = 0.116) decreased significantly in the ER group and the CG, respectively. Discussion: The present data show that a high-protein intake alone was not able to prevent lean mass loss associated with a 6-week moderate energy restriction in college students. Notably, it is unknown whether protein intake at 2.8 g/kg fat-free-mass prevented larger decreases in lean body mass. Muscle contractility was not negatively altered by this form of energy restriction. Sleep quality improved in both groups. Whether these advantages are due to the high-protein intake cannot be clarified and warrants further study. Although vigor was negatively affected in both groups, other mood parameters did not change.

Multilevel Evaluation of Rapid Weight Loss in Wrestling and Taekwondo

The practice of strategies for rapid weight loss (RWL) involve diverse factors, such as individual expectations, social interactions, structural elements, etc., conforming to a "culture" of RWL, which must be evaluated and understood in a broad sense. Based on the need of a comprehensive evaluation of the use of RWL in practitioners of combat sports, an ad hoc questionnaire designed for this study, which includes the types and detailed descriptions of RWL strategies, that athletes currently use, the prevalence and frequency of use, the physiological and psychological consequences, the perception of the effect of RWL on their own performance and finally, the individuals who influence the adoption of this practice. One hundred and sixty combat athletes from wrestling and taekwondo disciplines, from Mexico, filled out this questionnaire. Data collected for their statistical analyses. Results revealed a RWL strategies prevalence of 96% across the participants. Our results revealed that 57% of those athletes using RWL lose more than 5% of their body mass. Across the athletes, the most commonly used RWL strategies and with higher intensity were increased exercise and training with plastic or thick clothes. The greater the relative weight loss, the greater the presence of physiological symptoms in athletes, such as rapid breathing and blood pressure. Athletes also mentioned mood states such as tiredness, sadness, confusion, fatigue and vigor, these last two positive and negative mood states are associated with the relative weight loss, respectively. Finally, the people who most influenced the adoption of RWL strategies were the coaches, parents and nutritionists. In conclusion, the questionnaire prepared for this study allowed us to obtain valuable information about the several factors, and their interactions, involved in the practice of RWL in combat athletes. This type of practice could increase health risks and decrease their performance. Therefore, here we state the importance of a comprehensive evaluation of RWL strategies that allows the development of psycho-educational and social-based interventions and programs for the promotion of proper weight maintenance, and prevention against RWL strategies, involving the individuals who influence the adoption of these practices and supporting it with the help of communication technologies.

The Psychological and Physiological Consequences of Low Energy Availability in a Male Combat Sport Athlete

PURPOSE

This study aimed to evaluate the effects of low energy availability (EA) on health and performance indices associated with the Male Athlete Triad and Relative Energy Deficiency in Sport (RED-S) models.

METHODS

Over an 8-wk period, a male combat sport athlete adhered to a phased body mass (BM) loss plan consisting of 7-wk energy intake (EI) equating to resting metabolic rate (RMR) (1700 kcal·d-1) (phase 1), 5 d of reduced EI (1200-300 kcal·d-1) before weigh-in (phase 2), and 1 wk of ad libitum EI postcompetition (phase 3). EA fluctuated day by day because of variations in exercise energy expenditure. Regular assessments of body composition, RMR, cardiac function, cardiorespiratory capacity, strength and power, psychological state and blood clinical chemistry for endocrine, bone turnover, hydration, electrolyte, renal, liver, and lipid profiles were performed.

RESULTS

BM was reduced over the 8-wk period by 13.5% (72.5 to 62.7 kg). No consequences of Male Athlete Triad or RED-S were evident during phase 1, where mean daily EA equated to 20 kcal·kg·fat free mass (FFM)-1·d-1 (range, 7 to 31 kcal·kg FFM-1·d-1) and BM and fat mass (FM) losses were 6.5 and 4.4 kg, respectively. However, consequences did present in phase 2 when mean daily EA was consistently <10 kcal·kg FFM-1·d-1, as evidenced by alterations to endocrine hormones (e.g., testosterone <5 nmol.L-1) and reduced RMR (-257 kcal·d-1).

CONCLUSION

Data demonstrate that 7 wk of daily fluctuations in EA equating to a mean value of 20 kcal·kg FFM-1·d-1 permits reductions of BM and FM without perturbations to physiological systems associated with the Male Athlete Triad and RED-S. By contrast, a subsequent period of five consecutive days of EA <10 kcal·kg FFM-1·d-1 induced consequences of Male Athlete Triad and RED-S.

Self-confidence and Disordered Eating amongst Martial Artists: A Cross-sectional Study

Background: Extreme dieting is a well-known phenomenon in combat sports, and still, little research has explored the link between extreme dieting and confidence levels among martial artists. Methods: In this cross-sectional study, extreme dieting and sport-specific self-confidence among 111 Swedish athletes practicing mixed martial arts (MMA) or Brazilian jiu-jitsu (BJJ) were examined. Athletes completed an online survey containing the Eating Disorder Examination questionnaire (EDE-Q) and the Trait Sport-Confidence inventory (TSCI). Results: The results showed that MMA athletes dieted in more extreme ways than BJJ athletes, primarily via restricted eating. They also had higher sport-specific self-confidence, which was positively correlated with weight loss. BJJ athletes used less restrictive eating than MMA athletes, but those who did diet in extreme ways experienced lower self-confidence compared to MMA athletes. Conclusions: The results are consistent with previous studies showing rapid weight loss in MMA athletes and suggest that some martial artists are at a particular risk of extreme dieting and possible sequelae. There is a link between self-confidence and weight loss, but it seems to allude to a comprehensive explanation and is in need of further research.

Effects of gradual weight loss on strength levels and body composition in wrestlers athletes

BACKGROUND

Few investigations have evaluated isokinetic torque after a period of weight loss in wrestlers. Thus, the current study sought to investigate the effects of gradual weight loss in the precompetitive period on isokinetic peak torque in the upper and lower limbs and body composition in wrestling athletes.

METHODS

Eight elite athletes participated in the study (mean age 20.8±3.1 years). The athletes visited the laboratory on 2 occasions: during the period of weight maintenance (baseline) and during weight loss, in the precompetitive period (post). The variables analyzed were body composition through air displacement plethysmography (BOD POD) and peak torque (PT) of knee flexion and extension movements, and internal and external shoulder rotation in concentric action, at speeds of 60°/s and 180°/s, determined using an isokinetic dynamometer (Biodex Medical Systems; Shirley, NY, USA).

RESULTS

A significant decrease was observed in body composition values, except lean mass. No significant differences were observed in the PT of the movements analyzed: Shoulder internal rotation (60°/s P=0.825; 180°/s P=0.245) and external rotation (60°/s P=0.149; 180°/s P=0.163) and knee extension (60°/s P=0.086; 180°/s P=0.630) and flexion (60°/s P=0.310; 180°/s P=0.239).

CONCLUSIONS

Gradual weight loss did not affect the production of torque in the wrestlers before a competition. In addition, gradual weight loss contributed to a reduction in body fat, associated with an increase in percentage lean body mass.

Acute Effects of Supervised Making Weight on Health Markers, Hormones and Body Composition in Muay Thai Fighters

Making weight is a practice often used in combat sports. This consists of a rapid weight loss (RWL) and a subsequent rapid weight gain (RWG) in the days preceding competition. However, this practice is often carried out based on anecdotal information provided by ex-athletes or non-professionals, which has led to several adverse events. This study aimed to assess the acute effects of a supervised nutritional period of RWL/RWG on health markers, hormone concentrations, and body composition. We performed a single-arm repeated-measures (baseline, after RWL and after RWG) clinical trial with twenty-one (8F:16M) Italian Muay Thai fighters. Body mass was significantly lower after the RWL (-4.1%) while there was a significantly higher glucose availability after RWL and RWG. Blood urea nitrogen, lipid profile, and creatinine were within the normal range after RWL/RWG. Testosterone decrease significantly after RWL and RWG in the men group. Male fighters had a significant reduction in thyroid-stimulating hormone concentration after the RWL and RWG intervention, but no change was found in women at pre-competition. Bioelectrical parameters were almost fully restored after RWG. An evidence-based and individualized nutrition methodology reduces the adverse events after an RWL and RWG practice, although the impact on the hormonal profile is inevitable.

SEASONAL VARIATIONS IN BLOOD PARAMETERS AMONG KYRGYZ ELITE JUDO ATHLETES

ABSTRACT Introduction: Evaluation of health status and physical condition of Kyrgyz Judo Athletes before the Olympic Games. Objective: To evaluate changes in hematological, biochemical and blood gas values of athletes during the training period. Methods: Eight elite athletes (n=8 men), participated to the study. Before and after the exercise periods (baseline, 3rd month and 6th month), blood samples were taken, to determine plasma red blood cell (RBC), white blood cell (WBC), blood clot cell (PLT), granulocyte (NOTR) and agranulocyte (LNF) counts, hemoglobin (HGB) and hematocrit (HCT) values, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and venous blood pH, PO2, PCO2, SAT O2, HCO3, BE, Na, K, Cl values. In addition, serum glucose (Glu), total protein (TP), total cholesterol (TC), HDL cholesterol, triglyceride (Trig), blood urea nitrogen (BUN), creatinine (Creat), lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) values were measured. Results: Although, the athletes’ WBC and LNF counts increased significantly (p<0.05) in post-exercise periods, no statistical significance (p>0.05) was found in the other hematological parameters. Blood pH, pCO2, HCO3 and BE values decreased (P<0.05) after the exercise periods. Conclusion: The effects of exercise on judo athletes were evaluated before the Olympics. Level of Evidence III; Case-control study.

Reasons for and Consequences of Low Energy Availability in Female and Male Athletes: Social Environment, Adaptations, and Prevention

Low energy availability (LEA) represents a state in which the body does not have enough energy left to support all physiological functions needed to maintain optimal health. When compared to the normal population, athletes are particularly at risk to experience LEA and the reasons for this are manifold. LEA may result from altered dietary behaviours that are caused by body dissatisfaction, the belief that a lower body weight will result in greater performance, or social pressure to look a certain way. Pressure can also be experienced from the coach, teammates, and in this day and age through social media platforms. While LEA has been extensively described in females and female athletes have started fighting against the pressure to be thin using their social media platforms, evidence shows that male athletes are at risk as well. Besides those obvious reasons for LEA, athletes engaging in sports with high energy expenditure (e.g. rowing or cycling) can unintentionally experience LEA; particularly, when the athletes' caloric intake is not matched with exercise intensity. Whether unintentional or not, LEA may have detrimental consequences on health and performance, because both short-term and long-term LEA induces a variety of maladaptations such as endocrine alterations, suppression of the reproductive axis, mental disorders, thyroid suppression, and altered metabolic responses. Therefore, the aim of this review is to increase the understanding of LEA, including the role of an athlete's social environment and the performance effects related to LEA.

Effects of Rapid Weight Loss on Judo Athletes: A Systematic Review

Rapid weight loss (RWL) is commonly practiced among judo athletes. Although it helps them to gain the advantage over their lighter opponents, previous studies have shown that RWL can have a negative impact on the athlete's performance and overall well-being. This systematic review aimed to synthesize the evidence that examines the influence of rapid weight loss on physiological parameters, biomarkers, and psychological well-being in judo athletes. We followed the preferred reporting items for systematic reviews and meta-analyses guidelines. We searched for studies on Web of Science and PubMed that elaborate on the influence of ≥5% RWL achieved over ≤7-day period in judokas. Out of 52 studies initially found, 14 studies met our eligibility criteria and were included in the review. In total, we examined data from 1103 judo athletes. Retrieved studies showed conflicting data concerning physiological parameters and biomarkers, while psychological well-being parameters were more consistent than physiological and biomarkers. The feeling of tension, anger, and fatigue significantly increased while a decrease in vigor was demonstrated among athletes who lost weight rapidly. The evidence on the impact of RWL on performance remains ambiguous. More studies under standardized conditions are needed in order to provide firm evidence. Considering the harmful effects of RWL outlined in the existing literature, it is important to determine and monitor athlete's minimal competitive weight to prioritize the health and safety of the athlete, emphasize fairness, and ultimately benefit the sport.

Differences in the Bodyweight, Hydration Levels, Lean Mass, and Fat Mass in Spanish Junior Elite Judokas

Combat sports have a great interest in society and among professional sports. They are an important group of sports in the Olympic Games, but the strategies carried out by athletes to reduce body weight for weighing day, is famously known, suffering the adverse physical and psychological effects of rapid weight loss. This could compromise not only the performance, but the health and development of young athletes. A total of 22 elite male judokas (18.05 ± 1.05 years old) were evaluated during four different competitions in one season; the variables of body weight, water levels, and lean and fat mass were measured by bioimpedance (BIA), (Tanita BC545N) during one season. Using the linear mixed model test, we found significant differences in bodyweight variable during the competitions 3-4. The water level variable showed significant differences in all competitions, except for 2-4. Body mass index was significantly different in all competitions, being higher in the later competitions, except between competitions 1-2 and 2-3. Judokas participate in weight loss methods for their weigh-in days. Furthermore, the age at which the athletes reduced their water levels are worrisome. These results could be used to create healthy programs, especially in elite judokas, in order to carry out strategies before, during, and after competitions with weight loss and controlled water levels increasing future performance and health.

Four Weeks of Time-Restricted Feeding Combined with Resistance Training Does Not Differentially Influence Measures of Body Composition, Muscle Performance, Resting Energy Expenditure, and Blood Biomarkers

Recently, interest in time-restricted feeding (TRF) has increased from reports highlighting improvements in body composition and muscular performance measures. Twenty-six recreationally active males were randomly assigned to either TRF (n = 13; ~22.9 years; 82.0 kg; 178.1 cm; 8 h eating window, 25% caloric deficit, 1.8 g/kg/day protein) or normal diet (ND; n = 13; ~22.5 years; 83.3 kg; 177.5 cm; normal meal pattern; 25% caloric deficit, 1.8 g/kg/day protein) groups. Participants underwent 4-weeks of supervised full body resistance training. Changes in body composition (fat mass (FM), fat free mass (FFM), and body fat percentage (BF%)), skeletal muscle cross sectional area (CSA) and muscle thickness (MT) of the vastus lateralis (VL), rectus femoris, (RF), and biceps brachii (BB) muscles, resting energy expenditure (REE), muscular performance, blood biomarkers, and psychometric parameters were assessed. Significant (p < 0.05) decreases were noted in BM, FM, BF%, testosterone, adiponectin, and REE, along with significant increases in BP_1RM, LP_1RM, VJ_HT, VJ_PP, VL_CSA, BB_CSA, and BB_MT in both groups. Plasma cortisol levels were significantly elevated at post (p = 0.018) only in ND. Additionally, FFM was maintained equally between groups. Thus, a TRF style of eating does not enhance reductions in FM over caloric restriction alone during a 4-week hypocaloric diet.

Rapid weight loss influences the physical, psychological and biological responses during a simulated competition in national judo athletes

The effect of rapid energy restriction-induced weight loss on judo-related performance remains unclear, and there is a paucity of information regarding the influence of the fight successions during competition. Thus, the aim of this study was to compare the cumulative effect of judo fights on physical performance, biological and psychological profiles, of national judo competitors with vs without rapid weight loss. After one month of weight maintenance (Baseline), 20 subjects were randomly divided into two groups the week before a simulated competition: (i) a Weight Loss group (WL; weight loss ≥ 3% of body mass); (ii) a Weight Stable group (WS). The simulated competition was composed of five fights (F1 to F5) separated by 30 min rest. Anthropometric assessments were performed at baseline and on the morning of the simulated competition (T0). Psychological, biological and physical assessments (maximal handgrip strength, upper limb anaerobic capacity) were performed at T0 and after each fight. The variation of body mass between baseline and T0 was significantly different between groups (+1.2% vs -3%; p < .01). The dimensions of the Profile of Mood State questionnaire, the rate of perceived exertion, ammonia, urea and free fatty acid concentrations, maximal strength and time sustained at maximal strength showed a significant group x time interaction at F4 and F5. The study shows that cumulative fights lead to uncoupled responses in physical, psychological and biological parameters in judo competitors who underwent or not rapid weight loss. Specific recovery strategies in terms of nutrition and active recovery should be considered.

Precompetitional Weight Reduction Modifies Prooxidative-Antioxidative Status in Judokas

Objective

The main aim of the study was an assessment of the influence of rapid weight loss on oxidative stress parameters in judokas differing in weight reduction value.

Materials and Methods

The study included 30 judokas with an age range of 18-30 years (mean age: 22.4 ± 3.40 years). Enzymatic and nonenzymatic antioxidative markers, lipid peroxidation markers, and total oxidative stress were assessed three times: one week before a competition (the first stage), after gaining the desired weight (the second stage), and one week after the competition (the third stage).

Results

Between the first and the second stage, the concentration of lipid hydroperoxides (LPH) decreased significantly. The superoxide dismutase (SOD), copper- and zinc-containing superoxide dismutase (Cu,Zn-SOD), ceruloplasmin (CER), malondialdehyde (MDA), LPH, and total oxidative stress (TOS) concentrations were the lowest one week after the competition. Linear regression indicated that the emphases on increased weight reduction increased the activity of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and protein sulfhydryl (PSH) between the first and the second stage of the study. Moderate weight reduction (2-5%) resulted in elevated levels of SOD, Mn-SOD, LPH, MDA, and TOS in comparison to low and high reductions. An opposite relation was observed in PSH. In judokas, the precompetitional weight reduction range was 0.44-6.10% (mean: 2.93% ± 1.76%) of the initial body weight. Concentrations of superoxide dismutase (SOD; p < .01), manganese-dependent superoxide dismutase (Mn-SOD; p < .001), and ceruloplasmin (CER; p < .05) decreased between the first and the third stage of the study as well between the second and third one. Before competitions, a decrease in lipid hydroperoxide (LPH; p < .01) concentration was observed. A reduction of malondialdehyde (MDA; p < .05), LPH (p < .01), and total oxidative stress (TOS; p < .05) levels between the first and the final stage occurred. The increase in weight reduction was linearly correlated with the rise of glutathione peroxidase (GPx; p < .05), glutathione reductase (GR; p < .05), glutathione S-transferase (GST; p < .05), and protein sulfhydryl (PSH; p < .05) concentrations between the first and the second stage of the study. Moderate weight reduction (2-5%) resulted in elevated levels of SOD (p < .05), Mn-SOD (p < .05), LPH (p < .05), MDA (p < .05), and TOS (p < .05) in comparison to low and high reductions. An opposite relation was observed in PSH (p < .005).

Conclusions

The effect of weight reduction in judo athletes on prooxidative-antioxidative system diversity depends on the weight reduction value.

The Current State of Weight-Cutting in Combat Sports-Weight-Cutting in Combat Sports

In combat sports, athletes are divided into categories based on gender and body mass. Athletes attempt to compete against a lighter opponent by losing body mass prior to being weighed (i.e., 'weight-cutting'). The purpose of this narrative review was to explore the current body of literature on weight-cutting and outline gaps for further research. Methods of weight-loss include energy intake restriction, total body fluid reduction and pseudo extreme/abusive medical practice (e.g., diuretics). The influence of weight-cutting on performance is unclear, with studies suggesting a negative or no effect. However, larger weight-cuts (~5% of body mass in <24 h) do impair repeat-effort performance. It is unclear if the benefit from competing against a smaller opponent outweighs the observed reduction in physical capacity. Many mechanisms have been proposed for the observed reductions in performance, ranging from reduced glycogen availability to increased perceptions of fatigue. Athletes undertaking weight-cutting may be able to utilise strategies around glycogen, total body water and electrolyte replenishment to prepare for competition. Despite substantial discussion on managing weight-cutting in combat sports, no clear solution has been offered. Given the prevalence of weight-cutting, it is important to develop a deeper understanding of such practices so appropriate advice can be given.

Lean and mean? Associations of level of performance, chronic injuries and BMI in sport climbing

Objectives

To assess possible associations between performance level (achieved level of difficulty), chronic injuries and body mass index (BMI) in sport climbing.

Method

Retrospective survey.

Setting

Web-based questionnaire.

Participants

667 active climbers (385 reported having chronic injuries).

Outcome measure

BMI, performance level in sport climbing, onset of a climbing-related injury, preferred style of climbing, education, gender.

Statistics

Descriptive statistics and general linear model(GLM) performed with SPSS V.25 for windows.

Result

No associations were found between level of performance in sport climbing, onset of a climbing-related injury, preferred style of climbing, education, gender and BMI.

Conclusion

BMI is not associated with climbing-related chronic injury or level of performance in climbing. The average BMI of climbers up to the elite level is similar to that of a lower rate of performance.

Clinical relevance

The findings in this study suggest that there is no need for maintaining a low BMI to be able to reach elite levels in climbing.

Body Weight and Mood State Modifications in Mixed Martial Arts: An Exploratory Pilot

Brandt, R, Bevilacqua, GG, Coimbra, DR, Pombo, LC, Miarka, B, and Lane, AM. Body weight and mood state modifications in mixed martial arts: An exploratory pilot. J Strength Cond Res 32(9): 2548-2554, 2018-Mixed martial arts (MMA) fighters typically use rapid weight loss (RWL) as a strategy to make competition weight. The aim of the present study was to compare body weight and mood changes in professional male MMA athletes who used strategies to rapidly lose weight (n = 9) and with MMA athletes who did not (n = 3). Body mass and mood states of anger, confusion, depression, fatigue, tension, and vigor and total mood disturbance were assessed (a) 30 days before competition, (b) at the official weigh-in 1 day before competition, (c) 10 minutes before competition, and (d) 10 minutes postcompetition. Results indicated that RWL associated with reporting higher confusion and greater total mood disturbance at each assessment point. Rapid weight loss also associated with high anger at the official weigh-in. However, in performance, RWL did not have deleterious effects on performance. The RWL group also reported greater total mood disturbance at all assessment points with a moderate difference effect size. Research supports the notion that RWL associates with potentially dysfunctional mood states.

Rapid Weight Loss Is Not Associated With Competitive Success in Elite Youth Olympic-Style Boxers in Europe

Purpose: To examine the influence of rapid weight loss (RWL) on competitive success in elite youth Olympic-style boxers. In addition, this study examined the practice and prevalence of weight reduction, weight-management protocols, and related symptoms in youth boxers from 12 European countries (N = 83, all males, mean [SD] age 17.1 [0.9] y). Methods: The data were collected using an extensive questionnaire on weight cutting and its associated protocols and symptoms prior to highest-level continental championships. Competition results were obtained at follow-up using a dichotomous variable: medal winning vs nonwinning at the European Championships. Results: Binary logistic regression analysis indicated that “boxing experience” was significantly related to the criterion competitive outcome (odds ratio = 1.33; 95% confidence interval, 1.06–1.66; Nagelkerke R2 = .11), with a higher likelihood of competitive success for more-experienced boxers. Of all the youth boxers, only 25% were included in the RWL group, irrespective of their weight-class stratification. More than 45% of all the youth boxers self-reported the simultaneous combination of different weight-cutting methods that are known to be serious health hazards. Finally, 33% of the boxers experienced muscle weakness as a consequence of RWL. Conclusions: Our study provided evidence of pathogenic weight-management protocols that are widely adopted by youth boxers, and yet the present outcomes showed that RWL did not translate into competitive success in these elite Olympic-style boxers in Europe. Therefore, the authors suggest a mandatory educational program that should simultaneously target all the mentioned issues including both health- and performance-threatening consequences.

Diet-Induced Weight Loss Has No Effect on Psychological Stress in Overweight and Obese Adults: A Meta-Analysis of Randomized Controlled Trials

The effect of weight loss on psychological stress is unknown. The study aimed to investigate the effect of diet-induced weight loss in overweight and obese adults on psychological measures of stress through a meta-analysis of randomized controlled trials (RCTs). Databases including Medline Complete, Embase and PsycINFO were searched up to February 2018 for diet-induced weight loss RCTs, which included self-reported assessment of psychological stress. The mean difference between the intervention and control group of changes in stress (intervention-baseline) was used. Ten RCTs were included with 615 participants (502 women, age range 20⁻80 years). Overall, there was no change in stress (mean difference -0.06, 95% CI: -0.17, 0.06, p = 0.33) and no change in the five studies with a significant reduction in weight in the intervention group compared to a control group that lost no weight (mean difference in weight -3.9 Kg, 95% CI: -5.51, -2.29, p < 0.0001; mean difference in stress 0.04, 95% CI: -0.17, 0.25, p = 0.71). For all analyses, there was low heterogeneity. The benefits of weight loss for those who are overweight and obese do not appear to either increase or reduce psychological stress at the end of the weight loss period.

It is Time to Ban Rapid Weight Loss from Combat Sports

Most competitions in combat sports are divided into weight classes, theoretically allowing for fairer and more evenly contested disputes between athletes of similar body size, strength and agility. It has been well documented that most athletes, regardless of the combat sports discipline, reduce significant amounts of body weight in the days prior to competition to qualify for lighter weight classes. Rapid weight loss is characterised by the reduction of a significant amount of body weight (typically 2-10 %, although larger reductions are often seen) in a few days prior to weigh-in (mostly in the last 2-3 days) achieved by a combination of methods that include starvation, severe restriction of fluid intake and intentional sweating. In doing so, athletes try to gain a competitive advantage against lighter, smaller and weaker opponents. Such a drastic and rapid weight reduction is only achievable via a combination of aggressive strategies that lead to hypohydration and starvation. The negative impact of these procedures on health is well described in the literature. Although the impact of rapid weight loss on performance is debated, there remains robust evidence showing that rapid weight loss may not impair performance, and translates into an actual competitive advantage. In addition to the health and performance implications, rapid weight loss clearly breaches fair play and stands against the spirit of the sport because an athlete unwilling to compete having rapidly reduced weight would face unfair contests against opponents who are 'artificially' bigger and stronger. The World Anti-Doping Agency Code states that a prohibited method must meet at least two of the following criteria: (1) enhances performance; (2) endangers an athlete's health; and (3) violates the spirit of the sport. We herein argue that rapid weight loss clearly meets all three criteria and, therefore, should be banned from the sport. To quote the World Anti-Doping Agency Code, this would "protect the athletes' fundamental right to participate in a doping-free sport and thus promote health, fairness and equality".

The effect of 10 days of intermittent fasting on Wingate anaerobic power and prolonged high-intensity time-to-exhaustion cycling performance

Many physically active individuals have undertaken intermittent fasting to reduce their daily caloric intake. However, abstaining from meals for a specific length of time may lead to the acute disturbance of highly carbohydrate-dependent exercise performance. The purpose of this study was to observe the effect of 10 days of intermittent fasting on high-intensity type exercises, Wingate anaerobic (WT) and prolonged high-intensity time-to-exhaustion (HIT) cycling test. Twenty participants were randomised into an intermittent fasting (FAS) and a control group (CON). One day after baseline data collection on Day-0 where participants consumed their recommended daily caloric intake (FAS = 2500 ± 143 kcal day^-1; CON = 2492 ± 20 kcal day^-1) served over a course of five meals, the FAS group consumed only four meals where 40% was restricted by the omission of lunch (FAS = 1500 ± 55 kcal day^-1). This diet was then continued for 10 days. Data on exercise performance and other dependent variables were collected on Day-2, -4, -6, -8 and -10. A reduction in WT power in the FAS group was observed on Day-2 (821.74 ± 66.07 W) compared to Day-0 (847.63 ± 95.94 W) with a moderate effect size (p < .05, ES = 0.4), while HIT time-to-exhaustion performance declined over the 10 days with a trend of recovery from a large to a minimum effect size (p < .05, ES = 0.8-0.3). Body weight and triglyceride were consistently reduced in the FAS group (p < .01). The present study suggests that intermittent fasting must exceed 10 days to ensure that high-intensity performance does not deteriorate because this length of time seems to be required for effective adaptation to the new dietary regimen.

Effect of rapid weight loss and glutamine supplementation on immunosuppression of combat athletes: a double-blind, placebo-controlled study

The role of plasma glutamine concentration and glutamine supplementation on immunosuppression was investigated in combat athletes. Twenty-three male athletes were randomly assigned to receive glutamine (21 g/day, n=12) or placebo (ovalbumin, n=11) for 10 days. Six athletes who did not lose weight served as controls. Athletes were assessed 21 days before (−21d), 1 day before (−1d) and 5 days after (+5d) a competition. Weight reduction was similar between glutamine (−8.2%± 4.1%) and placebo (−8.5%±2.4%) and negligible in control (−0.6%±1.4%). In both weight-loss groups, the majority of athletes reported symptoms of upper respiratory symptoms, as assessed by the Wisconsin upper respiratory symptom survey questionnaire. Only two athletes reported symptoms in the control group. Immune cell function remained unchanged throughout the study except for an increase in neutrophil phagocytic activity (placebo: −21d=5,251±2,986; −1d=17,428±22,374; +5d=21,125±21,934; glutamine: −21d=6,096±3,549; −1d=11,029±17,113; +5d=28,186±21,032 FI) and a minor change in monocyte phagocytic activity (placebo: −21d=4,421±3,634; −1d=3,329±6,283; +5d=3,243± 2,553; glutamine: −21d=4,051±3,186; −1d=3,106±2,625; +5d=4,981± 4,598) in both glutamine and placebo after weight loss. Plasma glutamine and cortisol remained unchanged across the study. creatine kinase levels were increased in placebo (−21d=125.2±54.1; −1d=187.2± 73.5; +5d=111.3±59.1 U/L) but not in glutamine (−21d=136.2±58.2; −1d= 168.8±65.0; +5d=129.7±64.0 U/L). Rapid weight loss increased the frequency and severity of infection symptoms, but this was neither associated with plasma glutamine depletion nor counteracted by glutamine supplementation.

Hyperactivity of the Sympatho-Adrenomedullary System Without Any Modification of the Hypothalamic-Pituitary-Adrenal Axis After Food Restriction Among High-Level Weightlifters

Durguerian, A, Filaire, E, Drogou, C, Sauvet, F, Bougard, C, and Chennaoui, M. Hyperactivity of the sympatho-adrenomedullary system without any modification of the hypothalamic-pituitary-adrenal axis after food restriction among high-level weightlifters. J Strength Cond Res 32(6): 1643-1655, 2018-We examined the effects of 6 days of food restriction on salivary α-amylase (sAA), cortisol and dehydroepiandrostenedione (DHEA) awakening responses, psychological parameters and performance among 11 international weightlifters. Assessments were made at baseline (T1) and 6 days after a normal period of training while maintaining body weight (T2). Then, participants were assigned to 2 groups depending on whether they lost (Diet group) or maintained (Control group) their body mass. Anthropometric, psychological, physical, and physiological assessments were also realized 6 days (T3) after the restricted dietary period for the Diet group. Food restriction (T3) induced a significant rise of sAA awakening response (364.6%, p ≤ 0.05), whereas no significant variations were observed among the hypothalamic-pituitary-adrenal axis (cortisol and DHEA). Significant alterations of the general Recovery Score and General stress Score, evaluated through the Recovery-Stress Questionnaire for athletes, were noted after food restriction. Weightlifting performance, evaluated during a simulated weightlifting competition, was maintained after the 6-day food restriction; we even noted an increased weightlifting performance related to body mass (Sinclair coefficient). Our findings support the hypothesis that food restriction induces a challenging situation to the organism, resulting in an asymmetry between the 2 stress systems activation. These results reinforce the necessity to cautiously plan and monitor the weight regulation process before competition to avoid potential negative outcomes on psychophysiological parameters. In this regard, the psychobiological approach, especially the awakening responses, seems a useful tool.