The effects of rapid weight loss on skeletal muscle in judo athletes

Exercise Combined with a Low-Calorie Diet Improves Body Composition, Attenuates Muscle Mass Loss, and Regulates Appetite in Adult Women with High Body Fat Percentage but Normal BMI

BACKGROUND

The present study aimed to examine the effects of a 500 kcal reduction in daily energy intake alone and in combination with 90 min of moderate-to-vigorous aerobic exercise per week on body weight, body composition, and appetite sensations in young women with normal BMI and abnormal body fat percentage.

METHODS

sixty-six young women with normal BMI and abnormal body fat percentage (21.33 ± 1.20 kg/m2 and 34.32 ± 2.94%) were randomly assigned into three groups: (1) caloric restriction (CR; n = 22), (2) caloric restriction with exercise (CR-EX; n = 22), and (3) control (C; n = 22). Data on anthropometry, blood samples, and subjective appetite sensations pre- and post-intervention were collected.

RESULTS

After 4 weeks of intervention, CR and CR-EX groups both reduced body weight, fat percentage, and waist and hip circumferences compared to the C group (p < 0.05). Muscle mass of the CR group was significantly lower than that of the C group (-1.21 ± 0.86 kg vs. -0.27 ± 0.82 kg, p < 0.05), and no significant difference between CR-EX and C groups was observed. For appetite sensations, the subjects of the CR group showed significant increases in change of scores in desire to eat and prospective consumption than that of the C group (p < 0.05), while no significant difference between CR-EX and C groups was observed.

CONCLUSION

A 500 kcal reduction in daily energy intake alone and in combination with 90 min of moderate-to-vigorous aerobic exercise per week could both reduce weight and improve body composition in young adult women with normal BMI and abnormal body fat percentage. More importantly, calorie restriction combined with exercise intervention was superior to calorie restriction alone in improving muscle mass loss and regulating appetite sensations.

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.

Disentangling the dynamic interplay between muscle damage and energetics in male boxers during a short training block

Boxing is a combat sport linked to muscle damage (e.g., soreness, rising creatine kinase [CK]) and energetic biomarkers (e.g., urea, glucose). These factors have not, however, been examined dynamically in terms of day-to-day, lagged and reciprocal effects during normal training. This study investigated the dynamic interplay between muscle damage and energetics in male boxers during a short training block. Thirteen amateur boxers were monitored over 16 consecutive days during early-season training. The participants were assessed each morning for plasma CK, urea, glucose, and creatinine (days 1 and 16 only) concentrations, before self-reporting muscle soreness (1-10 scale). Within-person contemporaneous (lag-0) and temporal (lag-1) networks were estimated using multilevel vector autoregression. Muscle soreness, CK, urea, and glucose presented different trajectories with training, but with some heterogeneity reflecting within-person variances (47% to 78%). The contemporaneous network yielded a significant positive edge (or correlation) between CK and soreness (r = 0.44), along with negative CK-glucose and glucose-urea edges. More significant edges emerged in the temporal network, with soreness linked to CK (r = 0.19), glucose (r = -0.28) and urea (r = 0.22), whilst the CK-glucose edge sign switched. In summary, daily fluctuations in muscle damage and energetic activity, which presented in a normal physiological range, were highly variable among boxers during early-season training. Within-person networks indicated some interrelatedness between CK, soreness, urea, and glucose, although the nature and presence of these relationships were contingent on temporal ordering. These inconsistences reflect the pleiotropy of energetic biomarkers in training and recovery.

The Impact of Diet and Physical Activity on Fat-to-Lean Mass Ratio

In this retrospective study, we evaluated the efficacy of a personalised low-calorie Mediterranean Diet (MD) in promoting fat mass (FM) reduction while preserving fat-free mass (FFM). This study involved 100 Caucasian adults aged 18-65 years who followed a tailored low-calorie MD for two months. The total energy expenditure was assessed using a multi-sensor armband. The change in body composition (BC) was evaluated using the Δ% FM-to-FFM ratio, calculated as the difference in the FM to FFM ratio before and after the diet, divided by the ratio before the diet, and multiplied by 100. A negative value indicates a greater decrease in FM than FFM, while a positive value suggests a greater increase in FM than FFM. This study demonstrated a significant FM reduction, with an average decrease of 5% (p < 0.001). However, the relationship between caloric reduction and the Δ% FM-to-FFM ratio showed a weak negative correlation (r = -0.03, p > 0.05). This suggests that the calorie deficit had a minimal direct impact on the BC changes. Subjects over the age of 30 showed an increase in muscle mass, while younger subjects showed no significant changes. Moreover, a direct correlation was observed between the changes in MET (Metabolic Equivalent of Task) values and the Δ% FM-to-FFM ratio, indicating that improved average physical activity intensity positively influences BC. In the female subgroup, high protein intake, exercise intensity, and the duration of physical activity were positively correlated with an improvement in the Δ% FM-to-FFM ratio. However, for individuals with BMI 20-25 kg/m2, high fibre intake was surprisingly negatively correlated with the Δ% FM-to-FFM ratio. This study underscores the intricate interplay between calorie restriction, physical activity intensity, and BC changes. It also suggests that individual factors, including age, gender, and BMI, may influence the response to a low-calorie MD. However, further prospective studies with larger sample sizes are necessary to confirm and expand upon these findings.

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).

Prevalence of rapid weight loss in Olympic style wrestlers

Background

Methods

Results

Conclusions

Rapid weight gain following weight cutting in male professional boxers

OBJECTIVES

Weight classifications are used in boxing and other combat sports to match opponents of similar size. Professional boxers commonly engage in a potentially harmful practice known as rapid weight loss or 'weight cutting' to make weight the day prior to competition before rehydrating and refueling. This investigation describes the prevalence and magnitude of rapid weight gain in boxers following weigh-in as well as differences in practice with respect to weight class and promotion.

METHODS

This analysis describes official weight data from male professional boxers collected by the California State Athletic Commission between 2015 and 2018. A total of 399 athletes were included in the study.

RESULTS

Among included athletes, 389 (97.5%) athletes gained weight between official weigh-in and competition. Total absolute body mass gained was 4.4 ± 2.2 kg corresponding to a total relative body mass gain of 7.2 ± 3.5%. Boxers competing in international promotions gained significantly more body mass than regional competitors (8.0 ± 3.0% vs. 6.6 ± 3.7%; p < 0.001). In total, 82 (20.6%) athletes gained 10% body mass or more before competition. More international competitors reached this 10% threshold than regional competitors (25.3% vs. 17.4%; p = 0.03).

CONCLUSIONS

These findings indicate high prevalence and magnitude of RWG in professional boxing, particularly in boxers competing in elite international promotions.

Rapid Weight Loss of Up to Five Percent of the Body Mass in Less Than 7 Days Does Not Affect Physical Performance in Official Olympic Combat Athletes With Weight Classes: A Systematic Review With Meta-Analysis

Given the relevance of the effects that weight loss can generate on the physical performance in athletes, this study performed a systematic review with meta-analysis of the published literature on rapid weight loss (RWL) and examined its impact on the physical performance in Official Olympic combat sports athletes. The “Preferred Reporting Items for Systematic Reviews and Meta-Analysis” (PRISMA) guidelines were followed to ensure an ethical and complete reporting of the findings. PubMed, SPORT Discus, and EBSCO were the electronic databases explored for article retrieval and selection. The following string was applied: “RWL” OR “weight loss” OR “weight reduction” AND “judo” OR “wrestling” or “taekwondo” or “boxing” AND “performance.” Based on the quality analysis, conducted according to the “Tool for the assessment of study quality and reporting in exercise training studies” (TESTEX), ten articles achieved a score >6 points. The meta-analysis showed a significant difference in pre- vs. post-weight loss (p = 0.003) and no effects in pre- vs. post-power and strength performance analysis (p > 0.05 for both results). Based on our systematic review and meta-analysis of the literature, RWL up to ≤5% of the body mass in less than 7 days does not influence performance outcomes in Official Olympic combat athletes with weight classes, considering the strength and power measures.

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.

Rapid Weight Loss Coupled with Sport-Specific Training Impairs Heart Rate Recovery in Greco-Roman Wrestlers

Wrestling is a sport that can be classified with the use of alternating aerobic–anaerobic metabolism with moderate but high-impact energy expenditure. Heart rate recovery (HRR) is the difference between heart rate during exercise and a certain amount of time after the start of recovery. The goal of this study was to determine the difference in HRR between two phases: high-intensity sport-specific training (HISST) combined with rapid weight loss (RWL)—phase 1 (P1) and HISST only—phase 2 (P2). Ten national-level wrestlers were included in this study. All participants underwent HISST along with RWL procedures for P1. Seven days later, during P2, an identical training session was performed with no RWL included. We found a statistically significant difference in the values obtained after the first and second minutes of recovery in the second set for both cases (p = 0.034 and p = 0.037, respectively), with higher HR values recorded in P1. It can be concluded that there is undoubtedly a difference in HRR during training and RWL compared to HISST alone. Additionally, HISST along with RWL could compromise the aerobic component of recovery.

Changes in body mass and hydration status in judo athletes before and after a top-level competition: a descriptive case study

OBJECTIVES

The International Judo Federation (IJF) implemented new regulations in an attempt to regulate rapid weight loss in 2013. The body weight of the athletes cannot be more than 5% higher than the upper limits of their weight categories at the weight check for randomly selected athletes from each weight category before the competition. However, therea lack of studies demonstrating rapid weight loss and hydration status of elite judo athletes in a real match atmosphere under the current refereeing rules. Thus, this study aimed to examine the body mass and hydration changes of elite judo athletes a week before the competition, official weigh-in, and 24 hours after competition.

METHODS

Eight high-level male judo athletes voluntarily participated in this study. Body mass and urinary measures of hydration status were collected a week before, at the official weigh-in and 24-hour post-weigh-in.

RESULTS

The one-way repeated-measures ANOVA showed a significant main effect of time on body mass (p < 0.001). Body mass decreased by 5.4 ± 0.7 kg or 6.8% from a week before the competition to official weigh-in (p < 0.001) and increased by 3.0 ± 1.1 kg or 4.2% from official weigh-in to 24-h post-competition (p < 0.001). A significant effect of time was also found in both urine-specific gravity (USG) (p < 0.001) and urine color (UC) among the measurements (p = 0.001). Athletes' USG values were at the highest level (USG = 1.030 ± 0.001) at the official weigh-in, while they decreased significantly at 24-hour post-competition (USG = 1.017 ± 0.007).

CONCLUSION

The results showed that elite judo athletes resort to rapid weight loss and present dehydration despite established regulations by the IJF.

Weight Loss Strategies and the Risk of Skeletal Muscle Mass Loss

With energy intake restriction and exercise remaining the key diet and lifestyle approaches to weight loss, this is not without potential negative implications for body composition, metabolic health, and quality and quantity of life. Ideally, weight loss should be derived almost exclusively from the fat mass compartment as this is the main driver of metabolic disease, however, several studies have shown that there is an accompanying loss of tissue from the fat-free compartment, especially skeletal muscle. Population groups including post-menopausal women, the elderly, those with metabolic disease and athletes may be particularly at risk of skeletal muscle loss when following a weight management programme. Research studies that have addressed this issue across a range of population groups are reviewed with a focus upon the contribution of resistance and endurance forms of exercise and a higher intake dietary protein above the current guideline of 0.8 g/kg body weight/day. While findings can be contradictory, overall, the consensus appears that fat-free and skeletal muscle masses can be preserved, albeit to varying degrees by including both forms of exercise (but especially resistance forms) in the weight management intervention. Equally, higher intakes of protein can protect loss of these body compartments, acting either separately or synergistically with exercise. Elderly individuals in particular may benefit most from this approach. Thus, the evidence supports the recommendations for intakes of protein above the current guidelines of 0.8 g/kg body weight/d for the healthy elderly population to also be incorporated into the dietary prescription for weight management in this age group.

Patterns of rapid weight loss in elite sambo athletes

Background

Rapid weight loss (RWL) is commonly practiced in combat sports. Both magnitude and methods used to induce RWL are largely similar among combat sports, but currently, there is no data on RWL methodology used by sambo athletes. Therefore, the aim of this study was to determine RWL procedures sambo athletes apply to lose weight rapidly.

Methods

The sample consisted of 199 participants, of which 132 males and 67 females who participated in the World Sambo Championship 2020 held in Novi Sad, Serbia. Each participant received RWL questionnaire that was available in multiple languages, and every participant was instructed how to fill it out.

Results

Almost 87% of sambo participants declared to have intentionally cut their weight prior to the competition, whereby 5.27 kg (SD: ±7.57) was lost. Gradual dieting, sauna use and skipping meals were the most dominant methods used to reduce weight prior to competition while more extreme methods of RWL such as the use of laxatives, diuretics, diet pills and vomiting were also implemented but by much smaller fragment of the participants involved.

Conclusions

Findings from our study largely match with previously conducted RWL studies in terms of prevalence, magnitude and methods used by combat sport athletes, especially in judo and wrestling. Knowing the hazardous consequences of RWL, alternative methods of sustainable weight loss should be considered.

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.