Logging Workouts using fitbit/non walking type excersises

Hello Friends.

2 quick questions. New User of MFP. I wear a Fitbit Charge HR religiously.

Do you log exercise into Fitbit App or MFP App ?

1) Treadmill use... I will be going on the treadmill tonight and taking part in a couch to run program (run, jog, walk with various inclines) Do I keep my fitbit on and allow MFP and fitbit to sync ? How accurate will that be calorie burn wise... Or do I take it off and log separately when done. (but then if I do that, will fitbit go back and give me those steps ?)

2) Planks, Squats and Bowflex machine. New user to these as well and doing a plank, squat challenge for myself. How do I log those as exercise ? Or do you ?

Thanks a billion