I thought I had it roughly figured out. Based on my height and weight my basic metabolic rate (?) allowed for around 1950 calories a day.
Which I took to mean meant if I did nothing all day, I still burn 1950 calories.
So have set a goal to have a deficit of 750 a day, giving me around 1200 to eat.
A walk to the gym, a bit of running, rowing and cycling at the gym gives me a total of about 6k in distance and around 400 extra calories burned.
I've just signed up to the free trial of the Premium thing, and it is showing 1,100+ Activity Calories - based on the above I'm not sure how that figure is arrived at.
If anyone can shed any light that would be great - if I'm going to try to track this stuff it would be good to understand it as best I can!
Thanks.