RESUMO
Introduction: The ACTN3 gene encodes the α-actinin-3 protein in the Z lines of the sarcomere, which anchors the actin protein in the contractile apparatus, present exclusively in type II muscle fibers, presenting greater glycolytic capacity, which is essential for sports with high-energy actions. intensity and short duration as is the case with Volleyball. Objective: To verify the frequency and distribution of the ACTN3 gene, RR and RX genotypes that express α-actinin-3 (EX α-actinin-3), and XX genotype that do not express α-actinin-3 (NE α-actinin-3) and its association with Brazilian volleyball athletes. Materials and Methods: Nine-seven (97) athletes from the women's volleyball super league took part in the study. Body mass, height and age were evaluated to characterize the sample. Salivary samples were analyzed using (PCR) in real time, to determine the genotypes, and, to verify the association of the genotype with the status of volleyball athlete in the three categories (National Teams, Brazilian National Team and Brazilian Olympic Team), the test was carried out Chi-square of independence (χ²). To obtain the odds ratio of the outcome, a log linear regression analysis was performed. All tests were carried out using the JAMOVI 2.4 (2023) statistical software. Results: Among the athletes in the sample competing in the National Teams competition, 91.8% have the EX-α-actinin-3 genotype. When we consider Brazilian National Team competitions, 93.7% have the EX-α-actinin-3 genotype. Athletes who play for the Brazilian Olimpic Team, 100% of the sample have the EX-α-actinin-3 genotype. Considering that in the world population, the frequency is 80%, it is possible to verify that as you approach the athletes who participate in the women's team there is a greater participation of athletes with the EX-α-actinin-3 genotype. Furthermore, there was an association between the genotypes that EX α-actinin-3 and the National category, with the status of elite athlete, where (χ²) obtained the p value (0.023) and the rate ratio (2.71) for the outcome of the genotypes (EX α-actinin-3) being elite athletes. Conclusion: The athlete's genetic characteristics, environment, nutrition, physical, technical and tactical preparation are some of the factors that contribute to sports performance. However, the results of the present study suggest that athletes with RR and RX genotypes that express α-actinin-3, present in type II muscle fibers, seem to confer an advantage when playing high-performance volleyball.
RESUMO
BACKGROUND: The potential influence of genetics in athletic performance allows the search for genetic profiles associated with muscular work for the orientation of strength training and sports selection. The purpose of the study was to analyze four muscular exercises for effectiveness in improving explosive strength variables, associated to the genetics in Angiotensin Converting Enzyme (ACE) and α-actinin-3 (ACTN3) polymorphisms. METHODS: A randomized controlled trial was conducted on a sample of 80 subjects allocated into four groups: concentric muscle work (CMW), eccentric muscle work (EMW), concentric-eccentric muscle (C-EMW) work and isometric muscular work (IMW), by block and gender randomization. Vertical jump, long jump, power jump, and speed were measured to study explosive strength. Genotypic frequencies of ACE (rs4646994) and ACTN3 (rs1815739) were obtained by polymerase chain reaction. RESULTS: ACE gen showed significant improvements regarding the DD genotype in the Sargent test (p = 0.003) and sprint velocity test (p = 0.017). In the ACTN3 gene, the RR variable obtained improvement results with regard to RX and XX variables in long jump (p < 0.001), Sargent test (p < 0.001) and power jump (p = 0.004). CONCLUSIONS: The selected genes demonstrated an influence on the muscle work and the improvement in explosive strength variables with a decisive role regarding the type of muscle work performed.
