If it were just a matter of getting from one end of the court to the other, then any shoe would do for either sport. While there are some similarities between activities that are referred to as "running", and those which are also known as "tennis", they are actually two different games with their own particular sets of movements and requirements. Fortunately for runners who have suddenly found themselves in love with tennis (and all the practice it requires), there are a number of tennis-friendly running shoes which you can use.