The influence of the ACTN3 R577X polymorphism in the responsiveness to post-activation jump performance enhancement in untrained young men

ABSTRACT We aimed to investigate the influence of alpha-actinin-3 (ACTN3) R577X polymorphism on responsiveness post-activation performance enhancement (PAPE) countermovement jumps (CMJ) in untrained subjects. Sixteen men were allocated into two groups according their ACTN3 gene alleles: homozygous for X allele (XX, n = 9) or R (RR, 7). CMJ height, mean power output and vertical force determined twice (CMJ1 CMJ2) conditions: control (CON) potentiated (PAPE). In CON condition, performed before after a 15-min rest. PAPE 15 min 4 following five squats with 5-repetition maximum (5RM) load. Different conditions applied separate days randomized order. Statistical analysis involved three-way ANOVAs compare differences between (CON PAPE), time CMJ2), (XX RR). Significance level considered was p < 0.05. Effect sizes calculated as Cohen’s d. The effect changes height pre-activation 0.04 0.08, respectively. No significant found XX RR at baseline (1.07 ± 2.54 cm e -0.82 2.56 cm, respectively). (p>0.05) -0.20 1.6 -0.81 2.7 cm). conclude that polymorphisms does not PAPE.