Since you are already purchasing new shoes, you may have noticed that your old ones have worn significantly. Typically, the “life” of a shoe is around 350-400 miles. If your shoes look a little ragged, or you are positive they have reached the 400-mile mark, replace them with new ones. If you don’t know the mileage of your current shoes, look to see if they are as supportive as they should be. If you notice any signs of wear on the soles or tread, it’s time to pick up a new pair. When you are looking for new ones, ask a salesperson (if they are knowledgeable enough) if they know the life-span of the new shoes that you are buying. If they don’t know, do some research online and see if you can find out. It would be beneficial for you to know how long you will most likely get out of your new shoes and to be proactive when it comes to replacing them.