True. They do use other sensors to gauge the skin temperature and such. Coupling the data from that plus the accelerometer, you would at least be able to improv

True. They do use other sensors to gauge the skin temperature and such. Coupling the data from that plus the accelerometer, you would at least be able to improve upon the metrics calculated. From my understanding, it's not so much of the "seeing" of the pulse being the issue as the algorithms they use to cut off the data collection, identifying it as "noise". As a result, there is errant or missing data collection during rest periods (when optical oximetry wouldn't suffer due to the movement). If there's a sustained movement, using data such as skin temp and accelerometer makes it easier to identify what's noise and what not. Their calorie tracking really suffers due to the errant tracking of heart rate and the intense activity periods; comparing my off-days with workout days, the difference in calories burnt is a meagre 100-150 calories. A moderately brisk walk alone burns about 200 calories an hour. I suppose I was expecting some basic learning algorithms that adjust the data collection according to your day to day activities; but then this is the first iteration of the product, so there's hope. At this point of time, for me, it is just a sleep tracker + pedometer + a basic overview of the day.