Logging exercise with MyFitnessPal?

[KimMc60]

Sorry if this is an often-repeated question but I'm brand new to fitbits and I'm super confused. I synced the Fitbit app with MyFitnessPal. I'm currently doing Insanity Max 30, and when I workout I wear both my fitbit flex and my heart rate monitor. Is that what I'm supposed to do? Do I log the exercise on MFP or fitbit? The past few days I've logged my HRM calorie amount on MyFitnessPal (since it's more accurate - my fitbit hardly picks up any activity when I do Insanity) and let it sync to the fitbit app. One day I tried working out without my fitbit, only my HRM, and when I put the exercise into MFP fitbit changed my calorie adjustment to -250 (the same amount I'd just burned). I'm so confused about how I'm supposed to log my exercise - anyone out there who can explain it to me in the simplest way possible?  Thanks a lot!

P.S. Would it be most accurate to just log the exercise on MFP but then disable negative calorie adjustment?

[Transammatt]

I to workout with insanity max 30 .:) love it by the way. Have you looked into the Fitbit surge? Some target store have them in stock from time to time. I use my surge and it automatically connects with my fitness pal for the exercises. The surge has heart rate so I get A better accuracy on my calories burned. Just did Tabata power and burned almost 400 cal.

[KimMc60]

I would love a surge but my flex was a christmas gift and I don't have money for a new one, haha.