Polar or Fitbit???

BTW, a woman of your size will burn about 80-100 calories per mile, max, while jogging. 849 calories for a 6 mile jog is well outside that range.

I have both and they serve different purposes. I use the FitBit to track my daily steps and find myself walking extra if I'm near my goal. It is not good for tracking my workouts which are HIIT circuit usually incorporating core and weight work. I do wear it during workouts because we will often run during our session and want to count the steps. For workouts I use a Polar FT4 HRM and found the MFP calculations were nearly double what my HRM calculated. Also, I do not sync my FitBit to MFP because I didn't like it automatically adjusting my calories and knew there was a bit of doubling between FitBit and my HRM since I wear the FitBit during workouts.

FYI, HRMs do not estimate accurately for HIIT, and they are extremely bad for circuit training and resistance training/lifting.

I have both and they serve different purposes. I use the FitBit to track my daily steps and find myself walking extra if I'm near my goal. It is not good for tracking my workouts which are HIIT circuit usually incorporating core and weight work. I do wear it during workouts because we will often run during our session and want to count the steps. For workouts I use a Polar FT4 HRM and found the MFP calculations were nearly double what my HRM calculated. Also, I do not sync my FitBit to MFP because I didn't like it automatically adjusting my calories and knew there was a bit of doubling between FitBit and my HRM since I wear the FitBit during workouts.

FYI, HRMs do not estimate accurately for HIIT, and they are extremely bad for circuit training and resistance training/lifting.

Our sessions are usually 12-15 stations with a mix of cardio, weight resistance (body weight or plates/bars/bells), and core. We work for 40 seconds going as fast as possible or doing as many reps with as high a weight as possible depending on the exercise. We then have a 20 second rest session to catch our breath and move to the next station. Once I warm up, my heart rate is in the same range as it would be if I were doing steady state cardio like rowing or treadmill. Why would my HRM not be as accurate in this situation?

A variety of reasons. First of all, weight training increases your heart rate significantly, but does not burn many calories. Certainly not as many as the heart rate would suggest. This is why HRMs are terrible for any weight training.

On top of that, the heart rate induced by HIIT doesn't correspond well to calorie burn either.

The main reason for this is that tissue demands for oxygen can skyrocket for short periods of time during HIIT and weight training, but since it takes so long for blood to actually get from your lungs to those tissues heart rate is somewhat artificially inflated. The reason HRMs work well for steady-state cardio is that tissue demands are constant for longer periods of time, so heart rate can settle into a blood volume that works for the current demand over a while.

HRMs are intended for steady state cardio. It's only in steady state cardio that your heart rate can be reliably converted to a calorie burn, assuming you know what your VO2max is and the HRM is aware of it. They're not good at HIIT and weight training.

BTW, a woman of your size will burn about 80-100 calories per hour, max, while jogging. 849 calories for a 6 mile jog is well outside that range.

That's definitely more what I was thinking it should be. Is there a way to fix this on my HRM, or is it basically useless? I do like seeing my average heart rate, but I mainly got it to get a more accurate picture of how many calories I burn in each workout. Thanks!!

BTW, a woman of your size will burn about 80-100 calories per hour, max, while jogging. 849 calories for a 6 mile jog is well outside that range.

Do you mean per hour as that sounds really low? Should it be per mile?

I have both. I got the Polar FT4 to track my water exercises because the Fitbit One which is what I have isn't water safe. The Fitbit Flex is however. I do like the fact that the cardio machine at my local Y will sync with my HRM so no need to try to get the right grip on the machine to get my HR. However, I agree with the other I would get both if you can swing it.

IF you wanted to see what some of the graphs and Fitbit Feedback looks like, I did a blog post that includes a lot of visuals showing exactly the kind of things you see after wearing a Fitbit. I've had one for years, my two oldest now have them, and I got both my parents on board ... we are a Fitbit family!

http://jenbsjourney.blogspot.com/2013/08/wondering-about-fitbit.html