GPS devices make it easier than ever for runners to gauge that all-important number: the number of miles clocked. But in a new paper, researchers make the case that tracking mileage by itself presents too misleading of a picture. To better prevent injury and to improve training, runners need to factor in a slew of other factors that measure stress on the body, say the researchers. Consider cadence, for example. "If a tall person and a shorter person go out for a run, the shorter person could take thousands more steps than their taller teammate," says lead author Max Paquette, a biomechanist at the University of Memphis, per Running Magazine. "That run isn't the same total mechanical stress level for both runners," and it makes a big difference cumulatively. The portion of the paper dealing with injury risk is the most interesting, writes Alex Hutchinson at Outside.
For example, the researchers compared different scenarios—a soft trail with cushioned shoes, the same run while tired, a track session in spikes—to demonstrate the wide differences in pace, time spent running, total steps, the force of the foot smacking into the ground, etc. "At this point, it would be cool to give a formula for how you combine these and other variables to give you an estimate of how likely you are to blow your Achilles," writes Hutchinson. And while the new paper doesn't provide one, its authors say "emerging methods" should lead to better data and smarter monitoring. They acknowledge, however, that breaking runners of the habit of focusing on their weekly distance is likely to be difficult. (Is 6 feet enough distance from runners in the pandemic? Maybe not.)