COMT rs4680 Polymorphism and Exercise Motivation among Tennis Players and Swimmers

Background: Motivation plays a pivotal role in athletic performance. However, the genetic mechanism underlies motivated performance is unknown. A possible modulator of PA motivation is Catechol-O-methyltransferase (COMT), one of several enzymes that degrade catecholamines (such as dopamine, epinephrine, and norepinephrine). Catecholamines affecting a wide range of physical and psychological functions. COMT s4680 (Val158Met) is a single nucleotide polymorphism (SNP) in the COMT gene. The single nucleotide substitution between G--> A results in an amino acid change from valine to methionine at codon 158. The Met allele is associated with the lower enzymatic activity (due to thermos-instability), and with exploratory behavior.

Aim: The aim of the current study was to explore the association between COMT rs4680 Polymorphism and motivation among swimmers and tennis players

Methods: 76 tennis players and 57 swimmers participated in the study. Participants responded to aerobic/anaerobic motivation, mental toughness, and ego-task motivation questionnaires, and their genomic DNA was analyzed.

Results: Tennis players reported higher values of ego-oriented and anaerobic motivation and lower values of aerobic motivation compared to swimmers. Met allele carriers reported higher values of ego-oriented motivation compared to Val allele carriers. Moreover, tennis players, carriers of the Met-Met genotype reported higher values of internal motivation compared to swimmers, carriers of the Met-Met genotype.

Discussion: COMT Met allele is associated with more exploratory, lower COMT enzymatic activity, therefore higher dopamine levels, a lower pain threshold, enhanced vulnerability to stress, yet also more efficiency at processing information under most conditions. Indeed, Met allele carriers reported higher values of ego-oriented motivation. The difference between the reported motivation among Met-Met carriers who are tennis players and swimmers indicates gene-environment interaction.

Conclusion: We conclude that carrying Met allele is associated with higher ego oriented and internal motivation especially among tennis players. A direct linkage between COMT rs4680 Polymorphism, motivation, and sport was revealed.