I have a Fitbit Surge (I have talked about it before.) I bought it as a birthday gift to myself, specifically for the heart rate monitor. My thought was that it would push me to work out harder. I frequently check it by counting my own pulse, and mine seems to over estimate my pulse rate. I hooked myself to a pulse oximeter (a sensor that you hook on to your finger that checks your pulse rate and oxygen saturation level) at work to check the Fitbit pulse. The Fitbit pulse again was higher than the pulse oximeter.
There is a class action lawsuit against Fitbit, alleging that the pulse counts too low, especially at higher intensities. I turned to Consumer Reports, which I consider a fair, unbiased organization. Consumer Reports had previously tested Fitbit products and found them to be accurate. Consumer Reports retested both products. They had testers wear the Fitbits and hooked them up to an EKG machine (highly sensitive way to check heart rate.) Both devices were again deemed accurate.
Those filing the law suit say that their independent testing (also performed with EKG monitoring) demonstrated that the Fitbit was inaccurate up to 20 beats per minute.
So what to do with that expensive device hooked to your wrist? Test it yourself. Check a carotid or radial pulse. See if the Fitbit matches by your own pulse count, and check it at various exercise intensities. (Of course, if you have access to an EKG machine or a pulse ox, go for it!) One caveat: Fitbit did NOT market this as a medical device, so I don’t think you should get too bent out of shape if it is not accurate. Just my humble opinion….