I had a Versa 3 and used it during boxing and kickboxing workouts. It tracked my heart rate into the 190s. When it finally broke, I bought the Versa 4 due to the advertised heart rate tracking accuracy. Wrong!!! I can do one single punch on the heavy bag and the heart rate shows "--". Then, if you wait 10 seconds like Fitbit/Google suggests, it finally starts reading and isn't accurate. My heart can be pounding and I know it's at least in the 150s or 160s and it will show nothing or it might show about 109 or 110. I keep having to stop during my workouts in the hopes it will start tracking and show correct calorie burn over the course of the workout which it never does. I have tried all the troubleshooting I've seen so far and nothing helps.
