U.S. federal guidelines suggest that people get at least 30 minutes of exercise a day. Research now suggests that lack of motivation to exercise may be genetic. Studies show that many Americans are not meeting the minimum recommended amount of exercise.
For the study, Professor Frank Booth at the University Of Missouri College Of Veterinary Medicine used rats that were bred selectively. One of two traits was shown in the rats: they were either hyperactive or not active at all, lacking motivation. According to Booth and post-doctoral fellow Michael Roberts, genetics is linked to the motivation to exercise in humans, as well as rats.
"We have shown that it is possible to be genetically predisposed to being lazy. This could be an important step in identifying additional causes for obesity in humans, especially considering dramatic increases in childhood obesity in the United States," Booth said.
The rats were placed in cages with running wheels and monitored over a period of six days. The amount of time the rats spent running on the wheels helped researchers separate the active rats from the less-motivated rats. From the group, 26 rats who were excessive runners were bred with each other to create "super runner" rats. The less-motivated rats were bred with each other to create "couch potato" rats. The body composition and genetics of both groups were thoroughly evaluated.
"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 of rats," Roberts said.
Continued studies will help researchers get a better understanding of how genetics affect the motivation to exercise among people.
"It would be very useful to know if a person is genetically predisposed to having a lack of motivation to exercise, because that could potentially make them more likely to grow obese," Booth said.
The study comes out the University of Missouri and the findings were published in the American Journal of Physiology: Regulatory, Integrative and Comparative Physiology on April 3.
