Couch Potatoes may be Genetically Inclined to be Lazy

Some couch potatoes may have just been born that way.

A new study links certain genetic trains to those who may be a bit less physically inclined to do some hard work, or for lack of a better word, are  just plain lazy.

Scientists were able to selectively breed rats that were either extremely active or extremely lazy, and state that this indicates that genetics play a role in humans' willingness to exercise.

Study co-author Frank Booth, a professor at Missouri University, said that the study measured how many times each rat voluntarily went on a running wheel during a period of six days. The top 26 runners were then bred with each other, and the 26 laziest rats were also bred with one another.

After the breeding program had been repeated for ten generations, the line of active rats ran ten times more than the line of lazy rats.

The scientists examined varying levels of mitochondria in the rats' muscle cells, conducted genetic evaluations and compared body composition.

Co-author Michael Roberts said that "While we found minor differences in the body composition and levels of mitochondria in muscle cells of the rats, the most important thing we identified were the genetic differences between the two lines. Out of more than 17,000 different genes in one part of the brain, we identified 36 genes that may play a role in predisposition to physical activity motivation."

In the meantime, while researchers have not made any current plants to explore the effects of the identified genes on human's willingness to exercise, further research is need to determine the genetic link.

The study was recently published in the American Journal of Physiology.