Why track shoe mileage?

Cushioning, shock absorption and stability decrease over time and can cause unnecessary aches and pains or even injury.

Visual inspection is often not an accurate gauge of wear because the mid-sole, which takes the brunt of abuse from impact to push off, can wear out before the tread does.

Experts recommend replacing running shoes between 250 and 500 miles depending on your running style, body weight, and type of training.

But you don't have to take my word for it...

Runner's World: Running Shoe FAQ

Run The Planet: Why Do We Need To Replace Our Shoes So Often?

CNN Health: Get expert help in fitting running shoes