VANCOUVER — You’ve come home from work, you were planning on going to the gym, but you made the ultimate blunder: getting comfortable on the couch. You might say otherwise, but we all know that workout is now doomed. How is it that relaxing is simply so much more powerful than keeping our bodies in shape? A new study shows we may just have to chalk it up to our brains simply being hardwired to prefer hanging on the couch instead of the chin-up bar.
Researchers from the University of British Columbia and University of Geneva sought to better understand the brain chemistry behind what they refer to as the “exercise paradox.” This happens when people pledge to engage in regular physical fitness, but instead find themselves becoming less active.
The need for rest, of course, is evolutionary. Our earliest ancestors needed to avoid too much physical activity so that they had enough strength for hunting and gathering, finding and creating shelter, and all the other necessities for survival. Since we don’t face such demanding challenges today, we must force ourselves to find other ways to make up for the labor that came naturally to ancient humans.
“Conserving energy has been essential for humans’ survival, as it allowed us to be more efficient in searching for food and shelter, competing for sexual partners, and avoiding predators,” explains Matthew Boisgontier, a postdoctoral researcher in UBC’s brain behaviour lab at the department of physical therapy, and senior author of the study, in a UBC release.
So Boisgontier and his co-authors recruited 29 young adults who wanted to improve the level of exercise in their lives to take part in a computerized test. The test required them to move a human figure on the screen either towards images of physical activities or away from images of sedentary activities that would randomly appear, and then again vice versa. Participants were hooked up to an electroencephalograph to monitor their brain activity during the exercise.
The results showed that participants tended to move towards the active images or away from the sedentary ones at the fastest rates. “We found that participants took 32 milliseconds less to move away from the sedentary image, which is considerable for a task like this,” says study co-author Boris Cheval, of the University of Geneva, in a university release, adding that this finding went against the so-called exercise paradox.
That’s because the participants were simply following the instructions of the test, compounded by the fact that these were people who also wanted to be more physically active in their own lives. Their own reasoning pushed them to avoid that basic instinct of preserving energy and gravitating toward the less active images. This reasoning, however, involved more brain power — which is why the EEG measurements showed that moving away from the lazy activities required their brains to work harder.
“We knew from previous studies that people are faster at avoiding sedentary behaviours and moving toward active behaviours. The exciting novelty of our study is that it shows this faster avoidance of physical inactivity comes at a cost—and that is an increased involvement of brain resources,” says Boisgontier. “These results suggest that our brain is innately attracted to sedentary behaviours.”
The authors say people can always be encouraged to be more active if given the opportunity — such as installing fewer escalators or elevators in public places and instead using stairs or ramps. The more technology is designed to reduce physical effort, the more likely humans will “jump” on the chance to do less.
Of course, perhaps the need to give people more opportunities to be lazy might just be a product of that natural instinct to hop on the couch.
“The failure of public policies to counteract the pandemic of physical inactivity may be due to brain processes that have been developed and reinforced across evolution,” says Boisgontier.
The full study was published in the October 2018 edition of the journal Neuropsychologia.