(WKYC) -- Fitness trackers are a billion dollar industry with some researchers saying 60 million of us will wear them around our wrists by 2018. But are they really giving you the right information about your health?

Cleveland Clinic cardiologists studied several brands of chest and wrist trackers to rest the accuracy of each.

Here's how they ranked, from best to worst

  1. Polar H7
  2. Apple Watch
  3. Mio Fuse
  4. Fitbit Charge HR
  5. Basis Peak