When to Toss Your Running Shoes

You will notice when the tread has worn down so it no longer gives the traction and protection you need. Even if the tread looks okay, the material used in the insole to support your midfoot may have lost its buoyancy, so it can’t protect your feet from shock or hold your arch in place as you run. You will lose some of the spring with each step, reducing your performance and possibly opening yourself up to injury. The breakdown happens more quickly the heavier you are, or if you wear only one pair instead of rotating them. The problem is, you can’t see this microscopic process, so you need some other way to measure it.

Some runners simply keep track of the miles they put on their shoes, and change them out after they reach a limit—say 200 to 500 miles, or a bit more if you only run on grass and trails. Others give them a sniff test: if they smell bad even after washing , they may need to be replaced. You can try this measure, too: press the insole in various spots with your thumb. It should still feel firm and resilient. You can put one hand in your shoe, the other on the tread, and press together. If you can feel the fingers of the other hand, it’s probably time to say good-bye—even if it’s your lucky pair!