Originally Posted by Brittain

Maybe someone can point me to some unbiased studies, but I tend to think the idea that shoes need to be replaced after a certain number of miles is a myth perpetuated by the shoe companies (and repeated by endorsed athletes and coaches) in order to boost sales. That's not to say that shoes don't indeed wear out and need to be replaced, but that depends on a great deal more factors than "miles" put on them. How heavy your footfall is, where you run, the quality of the shoe in the first place, etc. I will replace my shoes for sure, but my feet will tell me when that time comes.