When recording heart rate, the FitBit site gives me three options.
Resting: I know what resting is. Most recommendations suggest taking that the very first thing in the morning.
Exertive: I am recording my average heart rate when I am doing vigorous exercise like running. I have a Heart Rate MOnitor strap and my Garmin watch records it and give me the maximum and average.
Normal: What is Normal heart rate?
Start by doing what is necessary, then do what is possible and suddenly you will be doing the impossible -- St Francis of Assisi
Rock 'n' Roll Dublin Half Marathon, Dublin, Ireland, 8/5/2013 ie.competitor.com/dublin/