A lot of us wear watches or trackers that are in charge of tracking a myriad of health markers from how many steps we get, to how our sleep last night was.  With the most common things being step count, heart rate, and caloric expenditure during exercise (calories burned when we workout), how accurate are these things we try to get this info from?!  As of right now, from some research by Xie et al., 2018, we know that the majority of wearable devices, most commonly, the Apple Watch and Fitbit, are reliable at tracking the information like step count, heart rate, and caloric expenditure.  While reliability may be the device’s strong suit, validity and accuracy is more of a rocky section for them.  A simpler way to look at it, is that the results from say, steps, heart rate, and caloric expenditure may be consistent from the device, but does the device actually provide an accurate measurement of those particular things?  While the validity / accuracy is continuing to rapidly improve, it has been found that they still fall short (2,3).  Ordinarily, it has been found that they overestimate quite often, in almost every regard (3).  Although this may be the case, and somewhat disappointing, what can we take away from this?  What we can take away is that we can get relatively consistent measurements to give us an indication as to whether or not we are way off of our normal routine or not!  Meaning that if normally you burn 500 calories in a workout, have an average daily heart rate of 87, and get 10,000 steps each day, and then one day in that same week you only burned 176 calories in a workout, had a heart rate of 98 as the average, and only got 3500 steps in, this could be indicative of a potential issue that we identified with the help of the wearable tracker!  In other words, it helps us see what is normal for us day-to-day, and then if we have a day that is way off and don’t really notice it, the tracker can pick up the slack in recognizing that and we can go back and maybe figure out why that happened, and where to go from there.  So, at the end of the day, the wearable devices we all have are reliable at giving information, but just lack a bit in accuracy, so we can track trends, but just need to take them with a bit of a grain of salt as the technology continues to evolve! 





  1. https://pubmed.ncbi.nlm.nih.gov/29650506/
  2. https://pubmed.ncbi.nlm.nih.gov/27270210/
  3. https://pubmed.ncbi.nlm.nih.gov/31219048/