All running shoes wear out eventually yet there's no universal formula which will tell you when to replace your running shoes. There are many factors that can affect the lifespan of a running shoe.
Some of these factors include:
- the miles you've run in them
- your weight
- your foot type
- the surface you run on
- the climate you run in
It's commonly accepted that most running shoes will last between 400 to 500 miles (give or take).This mileage range however, is just a guideline.
What Should I Look Out For?
There are some visible changes in your running shoes that may help you decide when to purchase new running shoes. Here are a few signs:
- a tear in the toe box
- one shoe has worn out a lot more than the other
- the midsole (responsible for shock absorption) cushioning has lost its function. One way to test for this is to press in the shoe with one hand and outside the sole with the other. If you can feel your fingers through the shoe, the midsole has likely lost its cushioning over time.
Your Body Type Will Impact When You Replace Your Running Shoes
Your body type also plays an important role in how quickly your shoes will wear out and need replacement.
A smaller individual who might weigh a little over 100 lbs will probably not wear shoes out quickly at all, since far less downward force is being exerted on body parts and shoes.
A much larger runner by contrast, will exert much more downward force on shoes, and wear out the midsole cushioning faster, as well as the soles of the shoes.
If you’re a person who buys into the old adage about running shoes needing replacement between 400 and 500 miles, the lighter runner would fall into the higher end of that range, and the larger runner would be on the lower side.
Your Mileage May Vary
Running on excessively worn out running shoes can change your running form without you knowing.
Changes to your running form can drastically increase your chance of a running injury.
The best approach to determine when you should replace your running shoes is simply to keep it personal.
Yes, you should keep an eye peeled for visible signs of wear on your shoes, but as long as your shoes still feel comfortable during a run, and you aren’t feeling any nagging little soreness or achiness, your running shoes are probably still good for a few more miles.
When you're ready to buy new running shoes, use my article "How to Buy Running Shoes" as a guide.