I have had my Garmin vivofit for a week now and was interested to see what it would record (in tandem with my heart rate monitor) for my hardest aerobic workout of the week: Cuba Tone. I was sure that I would register my highest heart rate since it is a high impact, high intensity workout, that leaves me a dripping mess on the floor. Looking at the stats I peaked at 174bpm which is in line with my recovery run heart rate peaks, averaging at 147bpm. Total calories burned: 576 (allegedly). By the end of the cooldown I was already back down to 88bpm and falling (my resting heart rate is around 55/56bpm).
A lot of running on the spot, so I don’t think the 5.12km can be considered accurate as a distance measure (it was counting my juggling as steps last night).