It seems like some people are just born to move while others are content to get their exercise by shifting positions on the couch and fumbling for the remote control. Teachers, coaches and parents have all had the experience of being around kids who are naturally very active or sedentary. But what causes this? Is it nature or nurture? Does a tendency toward wanting to exercise come down to a matter of genetics?
We’re Born Couch Potatoes
A kinesiologist from the University of North Carolina named Timothy Lightfoot did some experiments on mice that suggested living things have a tendency to be sedentary rather than active.
For muscular activity, sugars are needed. The name of the gene that controls the production of these sugars is AMP-activated Protein Kinase (AMPK gene). According to Lightfoot’s research, deactivating the AMPK gene resulted in mice that were less active. Researchers found other genes as well that were connected to physical activity.
It’s All in the Mitochondria
Cells need energy to function, and they get that energy from small units within the cells called mitochondria. Bodies are full of mitochondria, and the amount of mitochondria in the body goes up with greater activity. Lightfoot’s research found that not only were the mice with a deactivated AMPK gene less active but they also had less mitochondria. This seems to indicate that the AMPK gene and mitochondria are all related to how physically active people or even animals may be.
Nature or Nurture?
However, genetics and nature aren’t everything. Humans have many behaviors encoded in their genes that they have altered either as individuals or as societies. The fight-or-flight response is one example; most people who experience fear or frustrated do not immediately throw a punch or flee even though that is something distant human ancestors may have done. To some extent, being active and exercising is a learned behavior. Most likely, it is some combination. Scientists have found specific genes linked to activity in professional athletes but there is still much research to be done.
In the meantime, all children should be encouraged to be active, and adults can be excellent role models for children. Future DNA tests may someday accurately measure the likelihood of people being lazy or having other desirable or undesirable traits.
Genetic Study Dangers
Genetic research is still in its infancy. DNA testing has come a long way in just a few decades, and a US or UK paternity test can accurately identify a father. But the danger in genetic testing is that it may lead parents to assumptions about what their children can and can’t do including expecting them to be athletes or discouraging their activity because they don’t have the right genes anyway. Adults, too, run the risk of using genetics as an excuse for who they are and what they are capable of accomplishing. The fact of the matter is that genetics is one part of what makes people a certain way, but environmental factors are important as well.