After much online research of fitness trackers that have a heart rate monitor component, I decided to purchase the Fitbit Charge HR. I decided to go with fitbit despite having read some reviews indicating it was not as accurate with heart rate monitoring as a chest strap would be (such as paired with a polar or garmin activity tracker), but I really liked the idea of not having to wear the strap and I liked the style of the fitbit much more, so I went for it. I was very excited to open up the package, and get started... and that's about when my excitement over this thing ended. I really wanted to like this item... but I cannot believe how terrible this product is at completing even the most basic tasks... like tracking steps or distance...not to mention heart rate. I rarely take the time to write a review on amazon... I am doing so because I was so surprised at how terrible this product turned out to be! I was able to sync it to my phone easily... this is THE ONLY PRO I can offer for the Fitbit. From the very first time I put it on and for every time over the course of an entire month, I could not get it to track steps accurately...for example, I drove in the car and gained over 500 steps while sitting in a car for 7 minutes. Walking just 20 steps would give me 120. I read the entire online manual, tried making adjustments as suggested (changed the dominant/ non-dominant hand setting, measured and tried manipulating the setting for length of my stride)... these adjustments only made the fitbit inaccurate significantly in the other direction... I got on the treadmill and jogged 3 miles... fitbit said I'd covered 1.25 miles. At this point, I was curious as to how many miles would be equivalent to 10,000 steps… I was shocked to find that this should be 5 miles… because on the day that fitbit said I’d walked just over 10,000 steps, it also said I’d covered only 1.5 miles… (you can see this in the screen shot of my fitbit stats)…I don’t understand how that’s mathematically possible? I’m a 5.5 person, with normal stride, moving arms at normal rate, no reason it should be off like that. Another day, I’d logged over 6,000 steps, but fitbit said I’d only covered .03 miles. I attempted to resolve accuracy problems through fitbit customer service… which I found nearly impossible to locate contact info for. On the entire fitbit website, you are constantly directed to the fitbit “community” which is other users of the product (which I did try, but did not get any suggestion that helped) or you are directed to read the FAQ’s or manual….VERY difficult to find actual contact info for customer support. I had to do a google search for fitbit customer service, which is when I found out that they direct customer service thru twitter… (I thought that actually quite hilarious really… limiting all complaints to 144 characters!) This was when I began to understand the full story of what I now think fitbit is all about… all image, but no real expertise in the product…it’s just a pretty package. They are very responsive to you on twitter, suggesting you read the manual… but if that doesn’t work, they want you to resolve your issue offline, asking you to contact them via email to open a “case number”…which I did. After a few days, they responded with (direct copy and paste of the message they sent):We're sorry to hear that your having data discrepancy on your steps and mileage with your Charge HR.Thank you for trying different troubleshoot to fix the issue prior to contacting us. We'll be willing to assist you with this matter.Upon checking, we had confirmed in our system that your Charge HR last sync was 25 minutes ago via Android with a medium battery level.In the meanwhile, if you haven't already done so, please review our troubleshooting article. If you're still unable to sync after following the step-by-step instructions, please let us know.Please note that if you recently upgraded to OS 6.0 (Marshmallow) you must have location services turned on to sync your tracker. With this latest update, Google changed the permissions for Bluetooth syncing, requiring the use of location services. We are hard at work trying to find a work around for this new change from Google to ensure you can sync your tracker. (end of email response)This response just made me laugh…I had NOT had any trouble with the tracker synching… and also, I do NOT have the Android 6.0 Marshmallow update on my phone… and I DO have location services turned on at all times. Up until this point… I had assumed that somehow it must be me that was the problem…something about the way I move that’s not able to be picked up accurately or something. But when I got this email where they acknowledged my complaint about the inaccuracy of the tracker, stated they’d be handling it, and then in the next sentence, completely avoided addressing it and instead brought up something that was not a problem for me and that I did not complain about…I started to see that maybe there is another thing going on with this company.At this point, I decided to give up on the idea of tracking steps and instead just focus on heart rate monitoring since that was really the reason I’d bought it and I didn’t feel like going through however many more emails it was going to take to figure out the step thing anymore. Only one problem…I kept finding that the heart rate monitor was very unreliable… sometimes it seemed to function well and record my heart rate for the duration of a work out with accuracy (as compared to the heart rate monitors on the treadmills)… I’d have a nice set of stats/details to look at afterwards in order to compare workouts. Other times, it would show my heart rate on the tracker (during my work out), but then later, when I went to look up my workout stats online or on phone app, it would show the workout was logged but it didn’t capture my heart rate (and of course… not my steps or distance either!). On one of those work outs, I was jogging outside and tracking my run with “map my fitness” app on my phone… I have the exact date and times matching on that app’s log and my fitbit log… you can see for yourself in the screenshots that I included, map my fitness says I ran (actually it was just a walk) for 1.87 miles and it calculates over 4,000 steps… fitbit says I’m either a zombie or the heart rate tracker didn’t work and it logged zero steps and miles on this exact workout date and time. By the time I had decided it was time to return the fitbit because it was not able to do anything at all that I would have expected it to do, my daughter’s activity tracker had arrived (a Garmin Vivofit) and so I decided in one last attempt to determine…is it the fitbit or is it just something funny about the way I move that makes it so inaccurate at tracking my steps and distance… I decided to test the Fitbit HR charge against the Garmin Vivofit 2 (she didn’t order a chest strap, so no heart rate monitoring possible on this Vivofit). I put one on each wrist and jogged at my normal pace for 2.75 miles on the treadmill (according to the treadmill). Garmin said I’d taken over 6000 steps and jogged 2.73 miles. Fitbit said that during that workout, I’d added just over 3700 steps and covered less than half a mile. Case closed… the Fitbit HR Charge is the thing that’s not working… not me or the way I move my arms or my legs or my ability to sync or operate activity trackers…it’s Fitbit that doesn’t work correctly! Thank you Amazon for letting me return it!! And it looks like I’m ordering a Garmin Vivofit 2 with a chest strap! One other strange thing that started to happen with the fitbit… the last 2 times I wore it for a full day, I noticed that my arm was getting very sore and achy. The first day, it wasn’t connecting in my head that it would be related to the fitbit, I was just assuming my arm was tired or I’d slept on it wrong or something. The next morning though, it was worse, my arm was really sore and felt like it was burning from the inside… only the arm where I wore the fitbit, right about the spot where it sits was hurting. So I took it off and it took the entire day for that pain to go away. I decided to look up online to see if anyone else had had such a strange problem after wearing the fitbit… guess what… there are many people who’ve had this problem…some suggest it is related to radiation from the electromagnetic field that is created from the constant Bluetooth communication/ synching between the fitbit and the computer or cell phone. I am not qualified to propose any reason why it would cause my arm to hurt so much, but I do know that it certainly would have prevented me from wearing the tracker, even if it was accurate, if that pain would have persisted… so it’s something to be aware of if you’re considering a fitbit.