All the serious runners I know have their own GPS watches already, and chest straps to monitor heart rate. I only know a couple though, so it could be a biased

All the serious runners I know have their own GPS watches already, and chest straps to monitor heart rate. I only know a couple though, so it could be a biased sample. Or perhaps it is an age group difference, but I would think a doctor who is serious about his training would be a prime candidate for buying one though.