Nutrition, supplementation and weight reduction in combat sports: a review

Advantages of different dietary supplements for elite combat sports athletes: a systematic review and Bayesian network meta-analysis

With an increasing number of studies delving into the impact of dietary supplements on combat sports performance, researchers are actively seeking a more efficient dietary supplement for use in these sports. Nonetheless, controversies persist. Hence, we undertook a systematic review and Bayesian network meta-analysis to discern the most effective dietary supplements in combat sports by synthesizing the available evidence. We conducted a comprehensive search across PubMed, Web of Science, Cochrane, Embase, and SPORTDiscus, covering the period from their establishment to November 2, 2023. Our aim was to identify randomized controlled trials that evaluated the benefits of various dietary supplements for elite combat sports athletes. The risk of bias in these trials was assessed using the revised Cochrane Risk of Bias Tool for Randomized Trials. Subsequently, we employed Bayesian network meta-analysis through R software and Stata 15.0. During the analysis, we performed subgroup analysis based on the type of combat, distinguishing between striking and grappling disciplines. The analysis is based on 67 randomized controlled trials that meet all the inclusion criteria, involving 1026 elite combat sports athletes randomly assigned to 26 different dietary supplements or placebos. Results from the 50 trials included in the network meta-analysis indicate that compared to a placebo, sodium bicarbonate combined with caffeine (SMD: 2.3, 95% CrI: 1.5, 3.2), caffeine (SMD: 0.72, 95% CrI: 0.53, 0.93), beta-alanine (SMD: 0.58, 95% CrI: 0.079, 1.1), and sodium bicarbonate (SMD: 0.54, 95% CrI: 0.30, 0.81) was associated with a statistically significant increase in blood lactate concentrations. Compared to placebo, caffeine (SMD: 0.27, 95% CrI: 0.12, 0.41) was associated with a statistically significant increase in the final heart rate. Compared to placebo, creatine combined with sodium bicarbonate (SMD: 2.2, 95% CrI: 1.5, 3.1), creatine (SMD: 1.0, 95% CrI: 0.38, 1.6), and sodium bicarbonate (SMD: 0.42, 95% CrI: 0.18, 0.66) was associated with a statistically significant increase in mean power. Compared to placebo, creatine combined with sodium bicarbonate (SMD: 1.6, 95% CrI: 0.85, 2.3), creatine (SMD: 1.1, 95% CrI: 0.45, 1.7), and sodium bicarbonate (SMD: 0.35, 95% CrI: 0.11, 0.57) was associated with a statistically significant increase in peak power. Compared to placebo, caffeine (SMD: 1.4, 95% CrI: 0.19, 2.7) was associated with a statistically significant increase in the number of kicks. Compared to placebo, caffeine (SMD: 0.35, 95% CrI: 0.081, 0.61) was associated with a statistically significant increase in the number of throws. This study suggests that a range of dietary supplements, including caffeine, sodium bicarbonate, sodium bicarbonate combined with caffeine, creatine, creatine combined with sodium bicarbonate, and beta-alanine can improve the athletic performance of elite combat sports athletes.

A scoping review of rapid weight loss in judo athletes: prevalence, magnitude, effects on performance, risks, and recommendations

PURPOSE

Combat sports, such as judo, are weight categorized. Weight control was established to promote fair disputes among individuals. However, combat sports athletes adopt rapid weight loss (RWL) to obtain an advantage over smaller and lighter opponents. This scoping review article presents the prevalence, magnitude, and methods of RWL and its effects on physical and competitive performance, health risks, and psychological effects. Specific recommendations for attenuating the effects of RWL are also presented.

METHODS

Studies were retrieved from Web of Science, PubMed, and Scopus databases. Four hundred and forty-six articles were identified, of which fifty-three were considered eligible for this review.

RESULTS

The results showed that the prevalence of RWL was between 40% and 92.9% and that athletes reduced their body mass by approximately 5%. Although the literature suggests that RWL impairs the performance and psychological well-being of athletes, these results were obtained when recovery time was not provided.

CONCLUSION

No negative effects on performance were observed when the recovery time was >4 h. However, health risks due to RWL practices should be considered, and RWL should be avoided.

Sleep Behaviors and Nutritional Knowledge in Amateur and Professional Combat Sport Athletes

ABSTRACT

Dunican, IC, Galpin, A, Turner, M, and Reale, R. Sleep behaviors and nutritional knowledge in amateur and professional combat sport athletes. J Strength Cond Res 38(9): 1627-1634, 2024-Combat sports is a term applied to various competitive contact sports involving 2 competitors engaging in a bout or contest under a specific ruleset. Little is known about combat sports athletes' sleep and nutritional knowledge. This study aimed to assess (a) sleep behaviors, (b) alcohol and shiftwork disorders, and (c) the nutritional knowledge of combat sports athletes. Subjects completed various demographic questions and estimations of their weight management practices and validated surveys, including the Athlete Sleep Behavior Questionnaire, Shiftwork Disorder (SWD) Screening Questionnaire, Alcohol Use Disorders Identification Test, and the Abridged Nutrition for Sports Knowledge Questionnaire. A total of 844 combat sports athletes completed the survey, 79% male, height of 177 ± 10 (cm), and body mass of 79 ± 15 (kg). Subjects were categorized into their specific combat sport type (e.g., boxing or Brazilian jiu-jitsu [BJJ]) and by their level (professional or amateur). Sleep quality was average for all combat sport types and risk prevalence of shiftwork disorder at 11%. Mann-Whitney U tests revealed that amateurs, compared with professional strikers ( p = 0.046, CLES = 0.80), boxers ( p = 0.01, CLES = 0.78), and BJJ ( p = 0.046, CLES = 0.61) athletes, consumed significantly more alcohol. A Friedman test showed significant ( p < 0.001, W = 0.51) differences in weight between time points, with most combat sports athletes reducing weight for competition. An overall nutritional knowledge average of 55% was reported. This study highlights a critical gap in the knowledge and practices of combat sports athletes in relation to sleep behaviors and disorders, alcohol consumption, and nutritional knowledge, emphasizing the need for targeted educational interventions.

Assessment of Nutritional Status and Energy Availability of Indian Boxers

BACKGROUND

Inadequate dietary intake and low energy availability (LEA) negatively impact athlete's health, recovery, and performance outcomes. Currently, there is no Indian study that assessed the energy availability (EA) of Indian boxers and studied the contributing factors to LEA. This study was undertaken with the objectives of assessing the EA of Indian boxers (lightweight category) and correlating it with contributing factors such as anthropometric measurements, body composition, dietary intake, nutrient intake, and exercise energy expenditure.

METHODS

This descriptive cross-sectional study recruited 30 state-level boxers of the lightweight category (females: nine) residing in Mumbai, Maharashtra, India, using purposive sampling. Body composition was assessed using a body composition monitor. Anthropometric measurements were assessed using standard methods. Three-day exercise energy expenditure was calculated. Three-day dietary intake was assessed, which included two training days and one rest day using the three-day multiple-pass method. Dietary intake assessment included intake of all the meals, snacks, sports foods, sports, and dietary supplements. EA was calculated and participants were classified as moderate EA (30-45 kcal/kg FFM/day) and low EA (< 30 kcal/kg FFM/day). Descriptive and inferential statistical tests were conducted using Statistical Product and Service Solutions (SPSS, version 23; IBM SPSS Statistics for Windows, Armonk, NY).

RESULTS

Male boxers had a mean age of 18.43±0.93 years, and females had a mean age of 18.44±0.88 years. Among boxers, 36.67% (n=11) of participants were underweight, 46.67% (n=14) had a normal BMI, and 16.67% (n=5) were overweight. The mean body fat (%) for boxers was 13.11±1.8. Participants had insufficient consumption of different food groups before and after the energy intake adjustment. Processed packaged food consumption was popular among the participants. Various kinds of sports foods and supplements were consumed by a few athletes. Dietary supplements were not common among participants. The nutrient intake of the participants was inadequate. Participants could not fulfill energy/kg/day, carbohydrate/kg/day, protein/kg/day, and fat/kg/day requirements by 29%, 36.2%, 34.8%, and 23.9%, respectively. Iron and calcium intake was inadequate among female participants by 1.4% and 12.8%, respectively. Among male boxers, the mean EA was 29.71±3.74 kcal/kg FFM/day, and the mean EA of female boxers was 28.3±3.95 kcal/kg FFM/day. Around 66.67% of boxers in the present study had LEA, while the rest had reduced EA. EA had a moderately significant inverse relationship with fat-free mass (%). Energy intake was significantly related to EA and total body muscle % significantly moderated that relationship. The influence of fat-free mass (%), EEE (kcal), and energy intake (kcal) on the EA (kcal/kg FFM/day) was significant using multiple linear regression analysis.

CONCLUSIONS

The majority of the participants could not meet the food intake and nutrient recommendations. The majority of the participants had LEA. The higher the energy and nutrient intake, the higher the EA in the present study. EA had a moderately significant inverse relationship with fat-free mass (%) and exercise energy expenditure.

Nutrition for European Elite Fencers: A Practical Tool for Coaches and Athletes

The aim of this narrative review is to create a comprehensive, innovative, and pragmatic resource to guide elite fencers and coaches in making strategic nutritional choices to enhance performance and facilitate recovery. The literature review identified only 12 articles specifically addressing the topic of nutrition for fencers. Thus, the recommendations provided in this review derive also from articles dealing with similar sports, such as martial arts, and from investigations with European elite fencers and their coaches. For elite fencers, it is suggested to consume daily 7-11 g/kg of body weight (BW) of carbohydrates and 1.5-2 g/kg of BW of proteins and allocate 25% to 30% of the total energy intake to essential fats, with a specific focus on omega-3 fatty acids. The timing of meals, ideally within one hour after exertion, plays a pivotal role in restoring glycogen reserves and preventing injuries. The intake of leucine, creatine, omega-3, collagen, and vitamins C and D is proposed as a strategy for injury recovery. It is worth acknowledging that even when personalized plans are provided, implementation can be challenging, especially during competitions and training camps.

Nutritional Considerations of Irish Performance Dietitians and Nutritionists in Concussion Injury Management

Sport-related concussion incidence has increased in many team-based sports, such as rugby, Gaelic (camogie, hurling, football), and hockey. Concussion disrupts athletes' brain function, causing an "energy crisis" that requires energy and nutrient support to restore function and heal. Performance dietitians and nutritionists play a role in supporting athletes' post-injury nutritional demands. This study aimed to investigate Irish performance dietitians' and nutritionists' knowledge and implementation of nutritional strategies to manage and support athletes' recovery following concussion. In-depth, semi-structured interviews were conducted with seventeen (n = 17) Irish performance dietitians and nutritionists recruited from the Sport and Exercise Nutrition register and other sporting body networks across Ireland. Participants practised or had practised with amateur and/or professional athletes within the last ten years. All interviews and their transcripts were thematically analysed to extract relevant insights. These data provided valuable insights revealing performance dietitians and nutritionists: (1) their awareness of concussion events and (2) their use of nutritional supports for concussion management. Furthermore, the research highlighted their implementation of 'novel nutritional protocols' specifically designed to support and manage athletes' concussion recovery. There was a clear contrast between participants who had an awareness and knowledge of the importance of nutrition for brain recovery after sport-related concussion(s) and those who did not. Participants presenting with a practical understanding mentioned re-emphasising certain foods and supplements they were already recommending to athletes in the event of a concussion. Performance dietitians and nutritionists were keeping up to date with nutrition research on concussions, but limited evidence has prevented them from implementing protocols in practice. Meanwhile, participants mentioned trialling/recommending nutritional protocols, such as carbohydrate reloading, reducing omega-6 intake, and acutely supplementing creatine, omega-3 fish oils high in Docosahexaenoic acid, and probiotics to support brain healing. Performance dietitians' and nutritionists' use of nutrition protocols with athletes following concussion was linked to their knowledge and the limited scientific evidence available. Nutrition implementation, therefore, may be overlooked or implemented with uncertainty, which could negatively affect athletes' recovery following sports-related concussions.

β-Alanine Supplementation in Combat Sports: Evaluation of Sports Performance, Perception, and Anthropometric Parameters and Biochemical Markers-A Systematic Review of Clinical Trials

β-alanine does not have an ergogenic effect by itself, but it does as a precursor for the synthesis of carnosine in human skeletal muscle. β-alanine and carnosine together help improve the muscles' functionality, especially in high-intensity exercises such as combat sports. Therefore, β-alanine could be considered a nutritional ergogenic aid to improve sports performance in combat athletes. We aimed to critically review clinical trial evidence on the impact of β-alanine supplementation on sports performance, perception, and anthropometric parameters, as well as circulating biochemical markers in combat athletes. This systematic review was conducted following the specific methodological guidelines of the Preferred Report Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA), the PICOS question model, the Critical Review Form of McMaster, and the PEDro scale. Furthermore, the Cochrane risk-of-bias assessment tool was used. The search was carried out in the SCOPUS, Web of Science (WOS), and Medline (PubMed) databases for studies published from the beginning of the database until July 31, 2023. Of the 41 registers identified, only 7 met the established criteria and were included in this systematic review. Overall, performance parameters related to strength, power, total exercise work capacity, and combat-specific parameters were significantly improved (p < 0.05). Perception parameters increased non-significantly (p > 0.05). Regarding biochemical parameters, carnosine increased significantly (p < 0.05), pH decreased non-significantly (p > 0.05), and the results for blood bicarbonate and blood lactate were heterogeneous. Finally, there was a non-significant (p > 0.05) improvement in the anthropometric parameters of lean mass and fat mass. β-alanine supplementation appears to be safe and could be a suitable nutritional ergogenic aid for combat athletes.