Genetic markers and explosive leg-muscle strength in elite Italian soccer players.

Aim: The aim of the present paper was to investigate the relationships between polymorphisms in ACTN3, ACE and BDKRB2 genes, soccer performance, and explosive leg-muscle strength in Italian soccer players.
Methods: We examined 42 top-level Italian soccer players (S) and 106 sedentary healthy Italians, as a control group (C). χ2 test was used to look for the difference in genotype distribution of ACTN3, ACE and BDKRB2 between groups. The data were evaluated by forward stepwise multiple regression analysis with the Squat Jump (SJ) and Counter Movement Jump (CMJ) as dependent variables, as well as competition level (CL), ACTN-3, ACE and BDKRB2 genotypes as independent variables.
Results: No significant difference was found between groups for ACE, ACTN-3 and BDKRB2 genotype distributions. Forward stepwise multiple regression analysis suggests a significant relationship between a) SJ vs. CL, ACE, and ACTN-3 and b) CMJ vs. CL. For SJ, the multivariate model combining genotypic data and competition level significantly predicted explosive leg-muscle strength in soccer players and variance explained by the function was 23.92%.
Conclusion: An interaction of two polymorphisms (ACE and ACTN-3) might be able to discriminate quantitative traits crucial for the elite soccer performance, however the contribution of genetic factors to soccer performance is not so high.