Then, we analyzed the influence of different SOD2, CAT, and GPx1 genotypes on antioxidant enzyme activities (Table 3). In resting conditions significant differences were found only for water polo players having either the CAT −844 GA or GPx1 rs1800668 CT or TT genotype that exhibited greater SOD and GPx enzyme activities in comparison with wild-type athletes. Instead, all the examined polymorphisms did not affect CAT enzyme activity. Interestingly, the CAT-844 G>A genotype was also shown to be associated with a significant increase of postexercise GPX enzyme activity in comparison with wild-type CAT genotype GG, and the GPx1 rs1800668 CT genotype resulted to be associated with significantly increased postexercise CAT enzyme activity in comparison with wild-type GPx1 CC genotype. Surprisingly, the GPx1 rs1800668 TT genotype was associated with a significant reduction in postexercise GPx and CAT enzyme activities in comparison with wild-type GPx1 CC genotype. However, these results should be considered with caution given the small number of homozygous subjects that may be not representative of actual variations (Table 3).