Have you ever run on a paved path or road, then decided to step off to trot on a softer surface like grass or dirt, thinking the cushion-y ground is better on the body? Yeah, me too. Well, it turns out this move may be hurting us more then helping.
While running on forgiving surfaces like sand will make you work harder and can be a great fat burner in the short term, running on a surface like asphalt may be better for your joints in the long term.
A study in the Journal of Applied Physiology showed that when runners ran on soft ground, such as grass, dirt, and even treadmills, their bodies landed nearly three times stiffer than when they landed on asphalt. That means their knees, ankles, and hips flexed less, which over time significantly increases the chance of injury. (Imagine jumping, and not bending your knees as much as you normally would on the landing. Ouch.)
Still, many roads and even some running paths are cambered, meaning they're slanted to one side to help water run-off. Running along an angle, obviously, forces one foot to land slightly higher, which, according to research, can wreak havoc on your knees and ankles over time. If this sounds like your run route, try to find a flatter stretch of ground to step on.
—Mike Dawson is a magazine writer and editor, and a regular contributor to Details.