When traditional running shoes wear out, it’s typically because the midsole breaks down, losing its ability to support and cushion the foot. That breakdown has led to the standard—yet vague—recommendation that runners replace their running shoes after putting anywhere from 300 to 600 miles on them, depending on personal running style.
But minimalist shoes, by definition, have less cushioning and support than traditional running shoes. Therefore, there’s less midsole material—if any—to break down. With many minimalist shoes, runners can expect the shoe’s upper to fall apart before midsole breakdown becomes an issue. That’s not because the uppers are any less durable than those on traditional shoes, but because runners are able to put hundreds of more miles in minimalist shoes without having to replace them due to sole or midsole breakdown. The uppers tend to give first.
Broken uppers, however, aren’t always the ultimate cause of a minimalist shoe’s death. Runners have reported covering up to 1,700 miles on barefoot-style shoes like Vibram’s FiveFingers before the tread broke down on the soles, forcing a replacement purchase.
The bottom line: If you’re running in truly minimalist shoes with little-to-no midsole, pay attention to the tread to determine when you should replace your shoes. If the tread is getting worn down, it may affect how your foot strikes the ground, emphasizing any biomechanical inefficiencies you may have. And of course, if the uppers break and can no longer hold your foot properly in place, it’s time for a new pair.