The problem: Wearing old running shoes or wearing the wrong type of running shoes for your foot and running style can lead to running injuries.
The solution: Go to a running specialty store, where knowledgeable salespeople can evaluate your running style and foot type. When they determine whether you're an overpronator, underpronator, or neutral runner, they'll make shoe recommendations for you.
Once you get the right pair of running shoes, make sure you replace them every 300-350 miles because the loss of cushioning can lead to injuries. About halfway through the life of your shoes, you might want to buy another pair to rotate into your runs. Your running shoes will last longer when you allow them to decompress and dry out between workouts. Also, having a fresh pair of running shoes as a reference will help you notice when your old ones are ready to be replaced.