If you have a tendency to sit on the couch for hours on in rather than hitting the gym, there may be a genetic reason behind it.
A new study conducted by researchers at the University of Missouri suggests that there may be a hereditary trait linked to laziness. By studying a population of rats over ten generations, researchers concluded that there is such a thing as a genetic predisposition to laziness, at least among rodents.
To conduct the study, researchers placed around 50 rats in cages with running wheels. Over a period of six days, they recorded the amount of time each rat spent willingly running on its wheel. The rats were then separated into two breeding groups, so that the 26 most active rats bred only amongst themselves, and the 26 least active bred only with each other. The process was then repeated over ten generations.
At the end of the experiment, researchers discovered that the rats from the "super runners" line willingly ran 10 times longer per day on average than those from the "couch potato" line. To find which traits predisposed the active rats to working up a sweat, the researchers looked at several factors, including body composition and mitochondria content in muscle cells. But the most significant difference between the two populations was in their genes.
Though researchers have not yet determined if humans possess these same genes, there is a strong possibility considering rat testing has often been used as a gateway for breakthrough research among humans.