Humans are hard-wired to move in ways that require a minimal amount of energy. A new study in Current Biology from Simon Fraser University in Canada finds that while walking, people automatically adjust their gait to be energy efficient, adjusting their step width and frequency to do the least amount of work possible. 

The researchers, from Simon Fraser’s department of biomedical physiology and kinesiology, outfitted volunteers with robotic exoskeletons that forced them to adjust their gait by making them step more or less often than they would naturally as they walked on a treadmill. The participants adapted their step frequency to the optimum energy efficiency after just a few minutes of walking with their new gait, and did so even when the payoff was relatively small (less than 5 percent energy savings).

The robotic exoskeleton used in the study

As study co-author Max Donelan explains in a press release, “the nervous system subconsciously monitors energy use and continuously re-optimizes movement patterns in a constant quest to move as cheaply as possible."

So while you may go on a walk around the neighborhood hoping to get as much exercise as possible, your nervous system is actively making sure you do the least work you can. This makes a lot of sense when you consider that in the world of early humans, using less energy walking around normally might have left you a little extra energy in reserve to run away from a predator or catch up to your dinner. And, as the study points out, being able to constantly adjust your stride for efficiency might help people adapt to new tasks and different terrain, and avoid stride-inhibiting injuries. 

[h/t: Science News]

All images by Greg Ehlers