You meant to wake up early today, but you ended up pressing the snooze button for an hour. You were going to hit the gym postwork, but you opted for a Seinfeld marathon at home instead. You intended to make a healthful dinner afterward, but reaching for the phone to call in a pizza delivery took much less effort. Clearly, motivation is not your strong suit. But before you hang your head in sluggish shame, you might not be entirely to blame for your dormancy. Some evidence, albeit preliminary, suggests that a tendency toward laziness, at least when it comes to physical activity, may be genetic. Finally, the excuse we’ve all been waiting for! Or is heredity only a part of the story?
Of Mice and Men
Laziness (which, admittedly, is a problematic term, since each person defines it subjectively) is often thought of as a chosen, rather than a biological, trait. That’s precisely what piqued kinesiologist J. Timothy Lightfoot’s interest in the subject. He and his colleagues at the University of North Carolina, Charlotte, embarked on a series of studies, published in 2008 editions of the Journal of Heredity and Physiological Genomics, to determine if laziness could be traced to particular genes. Using mice bred specially to be active or inactive and then cross-breeding them to produce offspring with varying degrees of physical motivation, the researchers set up individual cages with exercise wheels and studied how fast and for how long each mouse ran voluntarily. The most active mice ran an average of five to eight miles per day. The more couch potato inclined ran a mere 0.3 miles. Even more tellingly, some of the lazy mice found other uses for the exercise wheel, such as sleeping (by putting wood shavings around the wheels) or going to the bathroom on it.
After surveying the mice for some time and comparing that data with their genetic makeup, the researchers found that certain genes influenced their activity levels. In fact, they concluded that heredity accounts for around 50 percent of whether a person is into exercise or into lounging. And these aren’t the first studies to link behaviors with certain genes. For example, a 1998 study showed that a sole gene determined whether fruit flies foraged for food or preferred to sit back. Even the difference between being a night owl and being a morning person is somewhat connected to heredity. But before Lightfoot and company’s work, biology wasn’t a part of the active-vs.-lazy debate. Of course, it’s important to remember that their tests were performed not on humans, but on mice, which Jeffrey Kluger, the science editor for Time magazine, called “good but imperfect templates” on the Today show in 2008. Definitive proof that the same kinds of genetic areas in humans make one person active and another less motivated is still pending.
Don’t Discount the Environment
After publishing the 2008 studies, Lightfoot and his colleagues said they were going to attempt the same results in a similar study involving men and women. What will come of that is uncertain, but even if a gene that makes exercising regularly that much harder for people does exist, it doesn’t mean those who have it are destined to live lazy lives. It does mean that they might need to be motivated through other methods, or find ways to make being active a normal part of their daily lives. Parking a little farther away from your destination or hiding your remote control are two suggestions mentioned during the 2008 Today segment; while they seem like small changes, they’re manageable and therefore perfect places to start. People who need extra inspiration could also invest in personal trainers or even enlist friends as workout buddies. All of this can happen with or without knowledge of a so-called laziness gene—perhaps especially without, since some could see it as an excuse or a justification, rather than something to overcome.
Ultimately, the findings of the University of North Carolina study, if they can be applied to humans someday, could mean that some people really do have a tougher time motivating themselves to exercise than others (yet another reason why we shouldn’t compare ourselves or our life choices with others, but that’s for another story). However, that doesn’t give us license to chew our families out for supplying the genes that make us skip yoga class week after week, either. What the study showed, and what much research has already suggested, is that traits like that are products of both environmental and biological factors. Just because we’re predisposed to act a certain way, have a certain addiction, or wake up at a certain time doesn’t set anything in stone. On the one hand, that’s pretty comforting to realize. On the other hand, overcoming biological impulses sure sounds like hard work. Sigh … can’t someone else do it for us?