It happens to me, but I am a walker, so it does it at 150 and 300. I haven't been able to figure it out, as my steps are higher than that. My max heartrate is 150 so I wondered if it meant I had reached my max heartrate, and to slow down. Then it shouldn't be a disco ball and look like a celebration, it should look like a warning. I don't think my heart could get to 300, so that is not it. I looked in the manuaI and everywhere I could find. I finally found this. I looked on here, and under another device people replied it was your active minutes. Since you get double minutes when heartrate is above fat burn status, it will differ from your active minutes your device or app shows. :=)
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