<b>The Genetic Link Between ACTN3 Variations and Physical Performance in Resistance Training Practitioners</b>

This study aimed to investigate the relationship between <i>ACTN3</i> polymorphisms and key physical performance parameters, including phase angle, one-repetition maximum (1RM) for bench press and back squat, and relative strength, in Brazilian strength training practitioners. 72 strength training practitioners (49 men, 23 women) and 450 age-matched male non-athletes were included in this study. Genomic DNA was extracted from buccal cells, and the <i>ACTN3</i> polymorphism (rs1815739) was genotyped using qPCR. Anthropometric measurements, phase angle (via bioimpedance analysis), and 1RM for bench press and back squat were assessed. Genotype and allelic frequencies were compared using Chi-square tests, and performance metrics were analyzed across genotypes using ANOVA and t-tests.