plaintiffs study of Fitbit accuracy (Score 1)

This study was not peer reviewed, and it appears to me that it has problems that would make it unpublishable. The methods section of the report describes data collection in a way that makes it clear that instructions for taking accurate heart rate readings in the Fitbit manual were purposefully ignored. These instructions describe stopping, staying still for a few seconds, and then taking a reading. This paragraph is just above the paragraph containing dominant and non-dominant wrist instructions which the report methods do pay particular attention to, so it could not have been missed. The description of data collection makes it clear that stopping and staying still was never part of the protocol since data was collected continuously during active exercise. The methodology used by Fitbit and all other wrist devices using light will never be accurate under these circumstances. The device is measuring the very small motions of blood vessels under the skin. If the device itself is moving, these measurements are disrupted. The scientists performing the study must have known this, so it is difficult to understand why there was at least no discussion of the Fitbit manual instructions and why they were dismissed in the text of the report. A reviewer, like me, would reject a paper with an omission like this. I performed my own series of scientific tests of the Blaze accuracy in March. Wearing both my chest band and my Fitbit for a week of 4 mile runs, and following the instructions, l found a difference of 2 beats per minute (bpm) with a standard deviation of 3.2 bpm at 95% of my maximum heart rate. I can understand consumers not reading the manual, initially, but eventually they should. A scientist performing a study, on the other hand... https://www.researchgate.net/p...