Running on soft surfaces (like grass or dirt) is supposed to be better for your joints than running on pavement. It makes sense that harder surfaces would be harder on your body, and so this wisdom has been passed down to plenty of runners. Too bad it's not true.
Photo by Michael Pardo
Dozens of studies have explored the effects of different surfaces on injury rates, and haven't been able to back up the oft-repeated wisdom. (Some, like this one in Foot and Ankle International, have even found less of certain injuries with hard surfaces.) How is this possible?
Even though your foot hits the ground harder on concrete, your foot and leg muscles adjust your stride to match, as shown by kinematics studies like this one published in Medicine & Science in Sports & Exercise. Peter Vigneron at Outside summarises:
[B]y subtly changing how we land, our bodies are pretty good at keeping impact forces constant no matter what we're running on. In layman's terms, that means most people unconsciously land a little softer when running on hard pavement, and a little harder when running on soft, pine-needle covered trails.
Trail running probably does prevent injury, but for a different reason: you use more muscles, in different positions, when navigating uneven ground. That helps strength and mobility. Read more at the link below, where Vigneron debunks a few more of your cherished running myths.
5 Running Myths Debunked [Outside]