Running is a simple sport as far as equipment goes. Generally, all that’s needed are the right clothes and, most importantly, a good pair of running shoes. But just how long does a quality pair of running kicks last? (Hint: Don’t ask Forrest!)

Hit the Ground Running — Why It Matters

When the Greeks ran foot races in the olden days, they usually did so barefoot and naked. Since then, running with clothes and shoes has become more of the norm (phew!), and with the advent of the modern day athletic shoe, perhaps a little more comfortable. Developed to be protective and add traction, running shoes have  evolved to incorporate lightweight materials that cushion the foot from the trauma of running [1]. Most cushioning comes from EVA foam, a lightweight material injected with air cells designed to absorb impact [1].

But, like all good things, the foam eventually loses its magic [1]. And according to some researchers, that can happen anywhere from 300 to 500 miles after the first wear [4]. So for a runner doing five 3 mile-runs per week, that comes out to a new pair every five to six months. (Let’s hope Santa comes twice this year!)

Don’t see the rush in picking up a new pair? Once that foam wears out, the risk of overuse injuries increases because the material has lost its ability to absorb shock [1]. While some overuse injuries (like shin splints) are minor, others (like tendinitis) might require more serious treatment.

The Sole-ution — The Answer/Debate

So what’s up with the range? Every runner has a different weight and foot strike, both of which affect the cushioning of the shoes in various ways. A bigger runner who runs on their heels may wear out the shoe cushioning faster than a light runner who runs on their toes.

But to eliminate all those miles of guesswork, here are some quick signs that those running shoes need to be replaced:

• Try the press test. Press a thumb into the center of the shoe, where the midsole is. If the midsole feels tough and unyielding, then it may be time for a new pair.
• Look for signs of creasing in the sole. If there are noticeable wrinkles in the midsole area, it’s a sign that the foam has been compressed beyond wear.
• Pay attention to aches and pains. While some say pain is weakness leaving the body, others say it’s an indication that something is wrong. A little twinge at the bottom of a foot could go a long way in saying that a shoe is past its prime.
• Compare new shoes with old ones. Comparing an old pair of shoes with a new one gives runners a direct comparison of what feels better. Once an old pair of shoes stops feeling comfortable, then it may be time to change them out.

Many these days, however, hit the road running barefoot or in minimalist shoes with almost no cushioning at all. But if it's decided that cushioned shoes are the way to go, just remember the cushion can only last for so long.

Certainty Level

Usain Bolt knows it’s all about the shoes.