FitBit and Gym workouts

sarahann104

I have just started going to the Gym in the last few weeks. I used to us a polar HRM but the bluetooth stopped working on it and changing the battery didnt fix it.
I've been doing an hour on a Precor AMT Or a half hour on the treadmill and a half hour on the AMT( I am waiting on a program to start my muscle group toning workouts) and using the steps logged from my fitbit charge HR and the sync with MFP for my daily calories.
I go quite hard on the AMT and am wondering how accurate the fitbit is for calories. Should i invest in another HRM.
I have on'y started using MFP again in the last few days and want to do it right:)
Thanks for any advice. Sarah