It was always thought that laziness was simply caused by a deficiency in motivation, wherefore a person made a positive decision to be active or inactive. However, recent studies have presented the idea that lethargy may in fact be genetically encoded. Kinesiologist J. Timothy Lightfoot and other researchers from the University of North Carolina have carried out several experiments on mice in order to test this theory. Lightfoot and his team bred two different types of mice – some with an active disposition and some without. These strains were then crossbred in order to produce 310 experimental offspring with hybrid genetics. At the appropriate age, each mouse was put in a cage with an exercise wheel, and the amount of exercise they completed within three weeks was observed and the mice were subsequently genotyped.
The exercise prone mice an up to 7 miles further per day than the inactive mice, and it was deduced that up to 50% of this difference could be attributed to heredity. It was also found that those genes which motivated activity were dominant within 75% of the more active mice. Lightfoot proposed two theories to explain this phenomenon. Firstly, he hypothesised that the way the muscles work may be influenced by genes – wherein they prevent fatigue by using energy more efficiently. However, researchers believe his second theory, where the motivation to exercise is caused by brain chemicals such as dopamine or serotonin, is far more likely. Research in this field is still developing, however, there is valid evidence to suggest that perhaps it’s our genes that prevent us from hitting the gym every day.
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http://www.time.com/time/health/article/0,8599,1827106,00.html?xid=rss-topstories
Student number: 42038665
