"Runners, pay attention to your mileage…on your footwear. Don’t put more than 300 miles on a pair of shoes—at this point, they’ll start to lose support and your body and muscles could suffer some painful consequences. (Think shin splints and sore calves. Ouch!)"

—Stevie Kremer was on the U.S. Mountain Trail Running team this past year and competed in the World Championships in Switzerland. She races—in her still-supportive shoes—almost every weekend.

As reported by Bethany Marzewski.