Why would running be the best way to lose weight fastest?

Well...: Any exercise can help you lose wt, assuming you are not eating more once you start working out. Running is nice because it's pretty simple for most people to do (get some decent or good shoes), and provides a pretty good workout, depending on how vigorously you run. If you have not been regularly exercising, may want to mix up your workout routines on different days. Running =great workout!