ACTN-3 and ECA genes expression do not influence the acute change in muscle mechanical and functional properties in youth handballers

The purpose of this study was to explore the potential relationship between ACTN-3 and ACE gene expression over the change in muscle mechanical and functional properties in youth handballers through a congested tournament. 30 players of the first handball division of Costa Rica participated in this study. The participants played a national tournament during three consecutive days (one match per day). The collection of genetic samples was through a mouth rinse with a 5% sucrose solution before the tournament. PCR tests were used to detect the alleles of the ACE and ACTN3 genes and the product´s reaction was visualized by electrophoresis. Before and after each match, tensiomyography (TMG) and Countermovement jump (CMJ) tests were used to assess mechanical and functional properties respectively. Descriptive frequency analyses and a one-way analysis of variance of independent groups were the statistics test applied. The results showed that the most prevalent polymorphisms expression was ACTN-3 R-X (56.7%) and ECA I-D (43.3%). No significant differences (p> 0.050) were found between genes expressed in the mechanical responses (contraction time (TC), delay time (TD) and, maximum radial displacement (DM)) of the rectus femoral muscle of the dominant leg neither in performance in the test CMJ. Likewise, there was no significant change (p> 0.050) in muscle mechanical or functional properties post official matches. In conclusion, handball players have the genes ACE and ACTN. Nevertheless, it seems to have no influence of these genes on the mechanical or functional muscles acute responses. More investigations will be needed to explain and understand the real impact of this gene’s expression on muscle performance in handball players.