Spend time around twins and you get a glimpse of a unique relationship. It’s more than finishing each other’s sentences—the DNA of identical twins isn’t quite identical, but it’s close (the DNA of fraternal twins mirrors those of regular siblings).
And, by studying twins, scientists are working to determine how environment, especially exercise, might change someone’s body and brain over time.
In a Finnish study published in Medicine & Science in Sports & Exercise, a team studied 10 sets of identical male twins, between the ages of 32 and 36. The twins had similar exercise habits to their sibling during childhood, but as they got older, one continued to exercise regularly and the other did not. Their diets were roughly the same.
Data showed the twins who exercised on a regular basis had higher endurance levels, lower body fat percentage, and proper blood sugar levels. All of this likely comes at no surprise to you.
What we found interesting, however, was that the researchers also saw an increase in the brain’s grey matter in the striatum and prefrontral cortex in the twin who exercised. “There were such clear site-specific structural adaptations in brain caused by exercise during adulthood,” said Dr. Urho Kujala, who led the study. The striatum is primarily involved in movement but it – along with the prefrontal cortex – also play a part in working memory. The prefrontal cortex is primarily responsible for decision making, problem solving, and processing immediate situations against how they fit with existing knowledge and memories.