When buying a pair of tennis shoes, you are making an investment. These shoes are the most important tool to get you through numerous runs and workouts. A Runner’s World article http://www.runnersworld.com/running-shoes/how-buy-right-running-shoes provides tips on what to look for when buying your shoes. Make sure your heel fits snug but not tight and make sure your toes have room for wiggle room since feet swell and lengthen over the time of a run. Shoes should match your arch contour. Try on the shoe but also make sure the shoe flexes along the same line your foot flexes.