Relationship between Taq1A Dopamine D2 Receptor Polymorphism and Motivation to Exercise and levels of Voluntary Physical Activity

Abstract

Sedigheh Sadat Hojjati, Hadi Rohani, Abbas Ali Gaeini, Mohammad shariatzadeh jonaidi

Aims: The purpose of this study was to examine the genetic basis underlying voluntary physical
activity. This study explores to an association, if exists, between motivation to exercise, levels of voluntary
physical activity and Taq1A gene polymorphisms. Method: 122 participants (age=24.4±5.7 yrs., 55 males & 67
females) completed the Behavioral Regulation in Exercise Questionnaire – 2 (BREQ-2) to assess their motivation
to exercise and the International Physical Activity Questionnaire (IPAQ) to assess their level of physical activity.
DNA was isolated from a cheek cell sample. The Taq1A genotype was identified using PCR with gene specific
primers. Results: Our study included 85 normal-weight, 30 overweight, and 7 obese subjects. Three variants
of DRD2 taq1A -CC (n=77, 63.1%), CT (n=35, 7.28%), and TT (n=10, 2.8%) - were identified. Internal motivation
to exercise was significantly higher in the CC genotype compared to the other two genotypes (P=0.017).
Conclusion: In general, intrinsic regulation factors of motivation, as well as the type of genotype, may play
a major role in determining the level of physical activity. Taq1A polymorphism of the DRD2 gene is related to
physical activity and body weight in young men and women.