Effects of Creatine Monohydrate on Endurance Performance in a Trained Population: A Systematic Review and Meta-analysis.

BACKGROUND: There is robust evidence that creatine monohydrate supplementation can enhance short-term high-intensity exercise in athletes. However, the effect of creatine monohydrate supplementation on aerobic performance and its role during aerobic activities is still controversial. OBJECTIVE: The purpose of this systematic review and meta-analysis was to evaluate the supplementation effects of creatine monohydrate on endurance performance in a trained population. METHODS: The search strategy in this systematic review and meta-analysis was designed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and PubMed/MEDLINE, Web of Science, and Scopus databases were explored from inception until 19 May, 2022. Only human experimental trials, controlled with a placebo group, evaluating the effects of creatine monohydrate supplementation on endurance performance in a trained population were analyzed in this systematic review and meta-analysis. The methodological quality of included studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale. RESULTS: A total of 13 studies satisfied all the eligibility criteria and were included in this systematic review and meta-analysis. The results for the pooled meta-analysis showed a non-significant change in endurance performance after creatine monohydrate supplementation in a trained population (p = 0.47), with a trivial negative effect (pooled standardized mean difference = - 0.07 [95% confidence interval - 0.32 to 0.18]; I2 = 34.75%). Further, after excluding the studies not evenly distributed around the base of the funnel plot, the results were similar (pooled standardized mean difference = - 0.07 [95% confidence interval - 0.27 to 0.13]; I2 = 0%; p = 0.49). CONCLUSIONS: Creatine monohydrate supplementation was shown to be ineffective on endurance performance in a trained population. CLINICAL TRIAL REGISTRATION: The study protocol was registered in the Prospective Register of Systematic Review (PROSPERO) with the following registration number: CRD42022327368.

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.