When it comes to walking, humans know how to take it easy. People can adjust their strolling style on the fly to save energy, researchers report September 10 in Current Biology.
The findings support the long-held idea that people pick the laziest way to move, says Alaa Ahmed, a neuroscientist at the University of Colorado Boulder. “It finally provides us with direct evidence that humans choose to walk in a way that reduces metabolic cost.”
But just walking slowly isn’t enough, says study coauthor Jessica Selinger, a neuromechanist at Simon Fraser University in Burnaby, British Columbia. To be efficient, humans have to find the right balance between a host of different variables that influence gait, including speed, step frequency and step width.