When Should You Replace Your Running Shoes?
This is such a common question I get from my patients and a really good one. In the past, the running
continuing education courses I attended consistently taught shoes should be replaced by 500 miles and a person should start breaking in their new shoes after about 350 miles so the new ones are ready to go by mile 500. Where did that magic number come from?
Well, it turns out that teaching was based on a study where they took a shoe into a lab, put it on a machine that pounded the shoe as if a person was landing on the heel of the shoe and the lab looked at what mileage the shoe started to break down and 500 miles was the max miles tolerated. In fact, the shoes started to break down after about 100 miles. That's not a lot of time for many runners before their shoes would have to be replaced if 100 miles was the max!
Now, this machine compressed the shoe constantly, without a break. The important piece to this is that shoe material has an elasticity or rebound ability to it. Unless your are an ultramarathoner, most of us are wearing our shoes for a much shorter period of time and miles, then taking them off. During that "off" time, the shoe materials can rebound and restore themselves back to whatever the level of cushion and support they are designed with (for a period of time at least. There is a shelf life to shoe materials and even without taking one step in them, they can start to break down after a couple of years.
If you shop at outlet mall shoe stores, you may want to ask how long the shoes are usually on the shelves). Due to the fact that shoes can rebound, and the many individual factors to each runner (how much they weigh, how many times a week they run, how many miles they run, outside or treadmill, etc, etc, etc) the current train of thought is that you should replace your shoes when they are no longer comfortable. That is not very specific or very helpful if you like concrete answers.
If you'd like, I have had some runners write the date they begin using their shoes and replace them after a year. Or replace them every 500 miles if that is what you're comfortable with. I personally can feel when my shoes just aren't right anymore and that's when they get replaced (usually about 1x/year). Use what works for you, but know that you don't have to be hard core about replacing your shoes every 350-500 miles.
Thanks for reading!