Running question???

Every now and then when I see people running they are wearing
a black band around their chest. It was only about an inch wide
and it was worn about mid-chest. Do you know what this is? I
thought maybe it was a heart monitor or something to help with
breathing. Thanks for any info.

You could be (probably are) describing a heart rate monitor. It keeps track of the heart rate over a period of time. I got one w/ the treadmill I bought.