What are those bars in the list of Riders.

I’ve looked every where and I’m sure I’ve probably over looked it but this is really driving me crazy.  Does anyone know what are the bars in the riders list on the right of the screen are?  The bars I’m talking about are near the mobile phone icon in the rows of some riders.  They don’t appear in all of them.  They look kind of like a small bar chart. I’ve noticed that I have them.




rider’s are doing workout !

Who have a heart monitor attached. (wrong)

Thanks for the quick responses.  

Just like the riders with the little dashboards out in front of their bikes.