Genes Influence Desire to Exercise

By studying 37,051 sets of twins, European researchers set out to see if this was the case. Identical twins share 100 percent of their genome, fraternal twins share 50 percent. So if a behavior is more common between identical twins than between fraternal twins, it is presumably being directed to some degree by genes.

In the 2006 study, scientists looked at the decision to exercise of twin pairs ages 19 to 40 in Australia, Denmark, Finland, the Netherlands, Norway, Sweden and the United Kingdom. Overall, the identical-twin pairs were more likely to share an exercise pattern than the fraternal twins.

Using complicated formulas, the scientists concluded that differences in exercise behavior were about 60% attributable to genes. In other words, the DNA you received from your parents does have an influence on your decision to be active or not.

 

Knowing this fact can't rule our lives, however. "Right now, most people don’t exercise, even though we all know that, for health reasons, we should," Tuomo Rankinen, an associate professor with the Human Genomics Laboratory at the Pennington Biomedical Research Center in Baton Rouge, La., and expert on exercise genetics, says. Maybe through our knowledge of genetics, ‘‘we can find ways to help make exercise easier or more attractive for people.’’

But no blaming DNA if you decide to skip a trip to the gym or that yoga class! ‘‘Even at the highest percentages of likely heritability’’ of exercise behavior, Mr. Rankinen says, the choice to exercise is yours.