We are programmed to be lethargic

If you have to force yourself off the couch to try to get some physical activity, rest assured you’re not alone. For decades, public relations campaigns have encouraged us to exercise, but an estimated 30% of adults are not busy enough. And this inactivity is growing everywhere on the planet.

France is no exception to this rule. If “more physical activity” is ranked in the top five good Modern Year’s resolutions, 75% of French people are not busy enough. And yet, according to the World Health Organization, 3.2 million deaths each year can be attributed to this lack of physical activity, or one death every 10 seconds.

This observation raises the question: why can’t we be physically busy, even when we want to?

Conflict between reason and emotion

To understand this struggle between our positive intentions and our conflicting impulses, scientific theories have been developed, such as dual-process models. In these models, the mechanisms that explain our behavior are divided into two categories: rational mechanisms, governed by the reflective system, and emotional mechanisms, governed by the impulsive system. The latter organizes the automatic and instinctive part of our behavior. It can facilitate or, on the contrary, prevent the reflective system from putting our intentions into action.

The latter case was clearly illustrated in our study. The aim of the study was to understand the conditions for the effectiveness of messages promoting physical activity. In other words, we wanted to find out whether reason can triumph over our impulses when it comes to motivating ourselves to be more physically busy.

First, participants had to attend a presentation that outlined recommendations for health-beneficial physical activity (30 minutes of exercise per day, spread over sessions lasting at least 10 minutes). To measure their impulsive tendency toward sedentary behavior, they were asked to perform an experimental task, the mannequin game.

This game involves moving around an avatar on a computer screen using a keyboard. In one of the experimental conditions, the participant has to move the avatar as quickly as possible towards images representing physical activity (walking, cycling, swimming…) and away from images representing a sedentary lifestyle (television, hammocks, escalators…). In the other condition, it is the other way around; the avatar has to be moved towards images evoking sedentary activities and away from images of exercise. The faster the participant has to approach sedentary images than away from them, the more their impulsive tendency towards a sedentary lifestyle is considered to be high.

We are not all equal when it comes to prevention messages

After this task, participants were given an accelerometer to record their daily physical activity and sent home. A week later, they were debriefed.

First, the results showed that participants who received a message promoting physical activity expressed an increased intention to exercise. Thus, well-formulated health messages appear to be effective in eliciting intentions. However, having the intention to exercise does not mean that one will actually do so, and not all participants were successful in transforming their intentions into behaviors.

Only those who had a low impulsive tendency to engage in sedentary behavior were successful. In contrast, participants with a high tendency were unable to transform their intention into action. In other words, the conscious intention to be busy lost the battle against the automatic tendency to seek sedentary behavior.

Why is a sedentary lifestyle attractive if it is harmful to health?

The Principle of Least Effort: Evolution’s Harsh Legacy

If this tendency to a sedentary lifestyle seems paradoxical today, it is logical when considered in the lithe of evolution. Indeed, when food was tough to come by, sedentary behaviors allowed us to conserve energy, which was crucial for survival.

This tendency to minimize unnecessary exertion may explain the current pandemic of physical inactivity, as genes that enable individuals to survive are more likely to be present in the next generation.

In a recent study, we wanted to assess whether our automatic fascination with sedentary behavior is hardwired into our brains. Participants in that study also had to play the mannequin game, but this time, electrodes measured their brain activity.

The results of this experiment show that in order to move away from images of sedentary behavior, our brains must deploy more resources than in the case of images of physical activity. In everyday life, moving away from the ubiquitous possibilities of sedentary behavior in our current environment (escalators, elevators, cars…) would therefore require us to overcome this sedentary attraction that is hardwired into our brains.

Effective, not lethargic

However, it is not true that we evolved solely to minimize unnecessary effort; we also evolved to be physically busy. Almost 2 million years ago, as our ancestors adapted to a hunter-gatherer lifestyle, physical activity became an integral part of their daily lives: they traveled an average of 14 km per day.

Natural selection therefore favors individuals who can muster a enormous amount of physical activity in an energy-saving manner. These are individuals whose physical activity was associated with the secretion of hormones that relieve pain, relieve anxiety, and even improve mood.

The good news is that these hormonal processes are always present in us, waiting for one thing: to be stimulated. The first step towards an busy lifestyle is to become aware of this force that pushes us to minimize effort. This awareness allows us to resist the countless opportunities for sedentary behavior that surround us.

Moreover, like our ancestors, most of us engage in physical activity only when it is fun or necessary, so the best way to promote physical activity is to make it enjoyable. Therefore, it is necessary to (re)structure our environment to support it, especially during daily excursions.

Public policy should, for example, develop safe and sound and well-maintained infrastructure and public open spaces to encourage access to places suitable for walking, cycling and other physical activities. The architecture of up-to-date buildings should also encourage physical activity during the day, giving priority to access to stairs or standing desks, etc.

Now it’s up to us how we employ these opportunities to reduce our sedentary lifestyle… So let’s jump into our sports shoes!