Whether walking or running for fitness there are two essential pieces of equipment that you should always own, and that is, two pairs of walking or running shoes.
So what is the importance of having two pairs when one is only necessary? The main reason is to avoid injury. Each set of shoes are made slightly differently, even if they came off the same factory line. Chances are that your two pairs even if they are of the same make, probably were manufactured at different times and maybe even different factories. The shoes will wear differently and this little difference can actually help you to avoid injury. If you own one pair and they wear the same way, which they will, then you can get an injury due to the constant stresses the shoes will place on the same area of your body. However, if you have two pairs and they wear differently then the stresses placed on your body will be distributed over different parts of your body, especially your feet, knees and legs. This “stress distribution” will actually help in avoiding overuse injuries.