For some runners, more may be less when it comes to the shoe padding. The increased cushioning in so-called maximal running shoes affect runners’ biomechanics. That, Oregon State University researchers have found, leaves them vulnerable to an increased risk of injury.

Maximal running shoes have about twice as much cushioning as typical running shoes. The intent is to maximize performance through comfort and stability. But the researchers determined that the extra padding, particularly in the forefoot region, affects a runner’s gait, which can lead to injuries.

Runners can avoid injuries by changing the way they run in maximal shoes, but, the researchers noted that isn’t happening. The conclusions were published in the American Journal of Sports Medicine.

The researchers conducted a pair of studies, the first of which assessed runners in maximal shoes before and after a five-kilometer race. The results suggested that maximal shoes may increase impact force and the speed at which it is applied.

The other study assessed how a six-week transition period to maximal shoes was affecting runner’s biomechanics. A group of runners who logged at least 15 miles a week were put through a series of trials wearing traditional and maximal running shoes. Over six weeks, they transitioned to maximal running shoes and gradually increased their distances.

The results showed no changes in running mechanics over time. But researchers did discover the maximal shoes were associated with higher impact forces.

Runners interested in trying out maximal shoes should take them for a test run on a treadmill or at a shoe store to see how they feel. Your feet should tell you what you need to know.