1. The watch is on tight. 2. The watch is set to elliptical workout. 3. During my 50 minute session there were 7-8 minutes throughout where my heart rate was in the 140s--I could feel it and the elliptical would say so as well--but AW would say it was in the 70s or that it could not get my HR at all. 4. My hands and body movement were consistent the entire workout. How can the AW be accurate one moment and for a long time and then without any body changes stop being accurate? Is there something I can do? Is this something I should take up with Apple? Do you think there is a problem with my specific watch? When I do Crossfit the AW is terrible at accuracy, but I thought it would be good given the consistency of the elliptical machine.