Fitness tracker discussion could use some tips

Hi there,

I have a Garmin Vivofit with seperate HR band and I am really happy with it and how it links into my fitness pal, however one bit really annoys me and that is that to start a activity I have to trigger the HR function via the tracker when I have the band attached and then once finished I click on it to stop and I am lead to believe that calories burnt etc will be based on your heart rate rather than a particular excersise.
The problem for me is everytime I sync my tracker afterwards it appears on Myfitnesspal as walking - slow pace etc when I have actually been weight lifting at the gym even if I change it in Garmin Connect.
Anyone have any ideas on how to change this?

thanks for your help