Does anyone have one of these, or know about them? They track activity and calories burned, although I assume this must be estimated since it doesn't monitor your heart rate - or does it? I don't think there's a chest strap involved. I'm interested in tracking my running activity, which I currently do using my iphone and mapmyrun app which tracks distance, speed and estimates calories based on this info. I'm wondering if the fitbit offers anything that my current method doesn't. I'm not really interested in tracking sleep, and I know it would be easier to carry/wear than a phone, but I tend to run with my iphone anyway in case I do a detour, get lost and need to refer to google maps
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