Accuracy in calories burned for circuit training/boot camp class (Charge HR)

tiffkittyw

Hi everyone,
I am aware that the Fitbit charge HR is only accurate for steady state cardio but I'm trying to gage whether or not when I set the workout mode for my boot camp class if Fitbit is overestimating or underestimating my calories burned. I'm 5'4" female, 38 years old and 127.5 lbs. I attached my workout summary from today's class for your review. Thanks!

heybales

That ability to choose a mode is merely for a text label - it changes no formulas.

First - great job getting up early - ugh. I only see 5am from one direction sadly.

The farther away you are from steady-state cardio - the worse the calorie estimate based on HR.

Lifting is like the extreme away from accuracy, along with cardio sprint intervals.

Circuit training or your boot camp is between, and since it's generally short, the accuracy while off isn't going to result in that many actual calories difference.

Now that you have an activity record showing what the calorie burn was just for that block of time - you can go back and manually make a workout record - pick Circuit Training as type, and take it's estimate of calorie burn.
The study that gave the formula to use was for 15-20 reps, up to 1 min of rest, and round robin of a circuit, and heavy weight for those reps, not easy.
If boot camp is similar, use that one just to see how far off the HR-based is.

The other thing is - as you become more fit, your HR should lower doing some of the same workout, but also higher doing others as muscle is stronger and can push you harder.
I'd expect you to have more time showing in the cardio range, and eventually the peak range.
The Fitbit should adjust to this fact, as resting HR goes down, and weekly exercise shows steady or more, and BMI goes down with weight loss.
But you can always review from time to time with doing exactly the above.
If just starting this boot camp, accuracy may be decent right now as you are learning moves and can't push that hard.

Oh, when you do the manual entry, the Workout record replaces the calories in the daily stats.
But the Activity record is a snapshot for that block of time and won't change. You can leave it for comparison, or delete it at that point - doesn't matter, and doesn't double up anything.

tiffkittyw

Thank you! Your responses are always so informative.