Dopaminergic Genetic Variants and Voluntary Externally Paced Exercise Behavior

Area of Science:

• Neurobiology
• Behavioral Genetics
• Exercise Science

Background:

• Candidate gene studies often link dopamine signaling to exercise behavior via the mesolimbic reward system.
• The role of executive functioning in mediating the relationship between dopaminergic genes and exercise remains underexplored.

Purpose of the Study:

• To investigate if dopaminergic candidate genes influence voluntary exercise behavior through executive functioning.
• To determine if accounting for exercise type (externally paced vs. total) enhances the detection of genetic associations.

Main Methods:

• Analysis of voluntary exercise data and dopaminergic gene polymorphisms in 12,929 participants from the Netherlands Twin Registry.
• Classification of exercise as externally paced based on executive function demands.
• Association testing of individual polymorphisms, a nine-allele polygenic score (PGS) for lower dopamine responsiveness, and a three-allele PGS for reward/executive function with exercise volume.

Main Results:

• No significant associations were found between individual alleles or the nine-allele PGS and total or externally paced exercise volume.
• A significant association emerged between the reward and executive function congruent PGS and externally paced exercise volume.
• The DAT1 440-bp and COMT Met alleles were identified as key increaser alleles for externally paced exercise behavior.

Conclusions:

• Considering exercise type, specifically externally paced activities, is crucial for identifying genetic variants associated with voluntary exercise behavior.
• This nuanced approach may improve our understanding of the neurobiology underlying exercise engagement.