Psychoactive drugs could be an effective way to encourage sedentary people to exercise, says a University of Kent professor.

“In my opinion, we have not paid enough attention to the core psychobiological reason for why most people do not regularly engage in physical activity: Humans do not like to exert effort,” Dr. Samuele Marcora, a professor at the school of sport and exercise sciences, wrote in his published editorial.

Improve the Mood, Improve the Body

While most of us know exercise is good for us, we still do not get out there and walk, bike, or jog as much as we should. And so health officials endlessly try new ways to encourage an exercise-resistant public to become more active. Doubtlessly, you’ve seen informational media campaigns and the creation of public places to exercise, such as the fresh bike trail through town or state-of-the-art pool at the community gym. Sure, a spanking new jogging track may be fun at first, but eventually most people drop out and stay home.

So how do you get people to maintain a behavior change once the excitement wears off?

You need innovative approaches to tackle this, argues Marcora, and past research suggests understanding our basic psychobiology would help scientists come up with them. Looking back to our earliest human history, the professor explains how wasting the “scarce resource” of energy via unnecessary physical activity would have reduced human survival in the face of disease and famine and requirements of a big brain, so our human evolution selected a “sloth gene.” In the past, the need to hunt, farm, go places, and fight provided motivation for remaining physically active.

“However, aversion to effort motivated us to progressively build the current hypokinetic environment,” Marcora wrote.

In other words, we humans are inherently lazy and our world —filled with comfy couches, ever-present TVs, drive-through restaurants, and non-existent suburban sidewalks — simply reflects that. Taking all of this into account, Marcora (the realist) suggests we all aim for moderate-intensity workouts, since they take comparatively less effort than high-intensity workouts and are slightly more pleasant. Going one step further, he suggests adding psychoactive drugs to the mix as a way to further reduce our “perception of effort and discomfort during exercise.” (Sure beats the standing desk...)

“I still remember the first horrified reaction of an exercise psychologist when I told him about this idea,” he wrote.


Still, his argument is less far-fetched than you might think. He notes, for instance, six of the seven drugs approved by the Food and Drug Administration for losing weight are appetite suppressants and few people raise ethical objections to this use of psychoactive drugs. Beside, Marcora adds, a psychoactive drug that reduces the perception of effort already exists: caffeine. In fact, he and his colleagues have conducted a short term study (a randomized controlled trial) to see whether caffeine is effective in sedentary people.

"We measured significant reductions in perception of effort. Moreover, we demonstrated a strong preference for the training sessions with caffeine (80 percent) compared to those with placebo (20 percent)," Marcora told Medical Daily in an email, adding that this first demonstration of changing behavior related to exercise needs to be followed by more extensive and long-term trials. In fact, he has one such study planned, where he will track participants for nearly a year as they take either caffeine or a placebo 30 minutes before aerobic exercise sessions. He says he expects a 50 percent drop out rate in the placebo group, much less in the caffeine group.

He also suggests studies be conducted to evaluate other stimulants “for the psychopharmacological treatment of physical inactivity.” Promising candidates include methylphenidate, already prescribed for attention deficit hyperactivity disorder, and modafinil, for sleep disorders. Both are already used off-label by people who want to improve their mental performance on tests or at work. At the same time, he says we might develop new drugs to help reduce the perception of effort during exercise.

"Drugs like modafinil seem to be pretty safe as well, although we still need to do more research on these stimulants," said Marcora.

In the end, Marcora gives new meaning to the term “runner’s high.” Still, his editorial highlights some valid points, which anyone who has ever taken a run or stopped by the gym following a drink after work would understand... even if they cannot entirely approve.

Source: Marcora S. Can Doping be a Good Thing? Using Psychoactive Drugs to Facilitate Physical Activity Behavior. Sports Medicine. 2015.

Emailed comments from Dr. Marcora were added to this article shortly after the initial online publication.