Phys Ed: Do Our Genes Influence Our Desire to Exercise? [news]

Is the urge to exercise bred in our bones? That’s the intriguing question that European researchers recently set out to examine by looking at the activity habits of 37,051 sets of twins. Twins are popular with geneticists, because they provide a neat statistical model for determining whether a behavior is influenced by genetics or exclusively by environment.

Identical twins share 100 percent of their genome, fraternal twins share 50 percent. All twin pairs, if raised together, share approximately the same early environment. So if a behavior is more common between identical twins than between fraternal twins, it is presumably being directed to some degree by genes.