Relation between the competition level and COMT Val158Met polymorphism in male competitive swimmers.

Daisuke ABE 1, Taishi ASAI 1, Hirokazu DOI 1, Shota NISHITANI 1, Yuusuke TAKAHASHI 2, Takaaki MATSUMOTO 3, Kazuyuki SHINOHARA 1

1 Graduate School of Biomedical Sciences Nagasaki University
2 Chuo University
3 Kokushikan University


A number of sports psychology literatures have identified the psychological factors such as the stress tolerance, aggressiveness, and motivations to be important determinant of the athletic competitiveness, and indicated that top athletes possess a set of psychological characteristics advantageous in showing good performance in athletic competitions. However, few studies have elucidated the neural basis of these psychological characteristics. In order to get insight into this point, we investigated the relation between the competition level of the competitive swimmers and COMT Val158Met polymorphism that is widely known to influence the dopaminergic nervous system activation.
56 male competitive swimmers representative of Japan class and the national convention non-participation class participated in the present study. Their competition levels were quantified by the self-record of the FINA point. COMT Val158Met genotype was determined on the basis of the DNA samples extracted from an intraoral mucous membrane cell. The participants were categorized into two groups (Met Carrier and Non-Carrier) according to their COMT Val158Met genotype. The analysis of the group difference has revealed significantly higher FINA point in the Met-carrier than in the non-carriers.
The previous studies have indicated that Met-carriers show higher level of attentional and executive control. On the basis of this, it seems plausible to think that the dopaminergic nervous system affects the competitiveness of swimmers by modulating the levels of self-regulation and concentration to the race.