Bests & Worsts Reviews from Amazon

I purchased the Flex based on a review claiming, "...technology is scary good...the pedometer George Jetson would have...the life-enhancing - perhaps life-changing - aspect of the Flex, is its ability to keep you focused on your exercise goals...it certainly is the most sophisticated device available today". I was further intrigued by claims of, "... it becomes part of your body: because it does so much and does it 24/7, you never want to take it off". From the Fitbit website, "This slim, stylish device is with you all the time. During the day, it tracks steps, distance, and calories burned." Nonsense. I should have known better since the reviewer received the device for free from the manufacturer over 4 months before public release. How It Works: The Flex at its core is a measuring device. Every output from it is based on tracking arm movement and interpreting whether that movement is walking, running, sleeping or other activities. Step count, calories burned and deep vs light sleep are the output. All measuring devices have a resolution. If you buy a 2 cup measure, you'll see graduations on the side, those are not just to help you know when you've filled to 1-1/4 cups, the distance between the graduations also indicates the accuracy of the device. The Flex displays calories and step counts in single units. It displays distance down to 0.01 miles. This indicates a high degree of accuracy. However, if you're not interested in accuracy but in motivational value, then don't bother reading on, get one, you'll love it. The Review: First of all, I have no association with anyone or any company in the health and fitness segment. I purchased two, one for me and one for my wife. We wore the devices for several days and ended up exchanging both for Fitbit Ones (which I would highly recommend if you want accuracy in a device you can wear 24/7). I was really looking forward to the Flex. In fact I had initially bought a One and returned it due to the claims made by Fitbit regarding the Flex. Specifically, I wanted to track my sleep, activity and calories burned. Essentially, I wanted a device I could wear 24x7, charge once a week and it would sync wirelessly with my phone or computer. Those it does just fine. As for the real reason you may want one; to accurately monitor your physical activity throughout the day, it's severely lacking. Pros; - Small, wireless, easy to charge - Charge lasts for days - Contains a vibrating alarm - Overall, the iPhone and online app aren't too bad - Tracks walking and running extremely well (both step count and distance) - Only registered a few steps when driving (some pedometers register a large number) Cons; - Don't expect accurate step or mileage counts if you wear it all day regardless of calibration - Because of the above, don't expect to get an accurate picture of the amount of calories burned - If you're interested in tracking food, be aware the option is several layers deep in the app - Water doesn't drain out if you wear it in the shower (I would recommend taking it off beforehand) - Initially, it's extremely difficult to latch, my wife couldn't do it without assistance What I Tested: I tested the device over several days of activity including walking, push-mowing the yard, riding in the car, pushing a shopping cart. Before the end of the first day, I had logged well over 10,000 steps and 6 plus miles. Well, the device said I did anyway. Really, there's no way I walked more than a couple miles at most. The results were consistent across several days. It always vastly over rated my activity (I would have much less of a problem with the device if it did the opposite). How I Tested: I decided to pay more attention to my activities and whether the Flex was counting steps properly. The smartphone app allows for real-time monitoring of the device so it's easy to test. I noticed that when I pushed a shopping cart I logged exactly zero steps. No matter what I tried, as long as my hands were on the bars, it wouldn't log (Fitbit claims it does log steps when pushing a shopping cart). Expect similar results when pushing a stroller. When I push-mowed the yard, I logged a couple of miles. Based on the yard dimensions and mower width, I calculated the distance as 3,100 feet or less that 0.6 miles. That's an error rate of over 300%. The problem is that the Flex can't effectively distinguish between different kinds of wrist motions. To the Flex, clapping for your kid's goal is the same as walking. To test, sit on the couch, hold your wrist at chest height and shake it a couple of inches up and down rapidly to register well over 100 steps in 10 seconds. Like hip-based pedometers, wrist-based pedometers use 3-D accelerometers to determine when you're walking or running. They have an extremely difficult time determining whether that motion is your body actually moving or whether it's your arm moving and your body's stationary (that's why there's an option for dominant hand selection). So the problem for me is accuracy. If the device doesn't know whether I'm walking or eating popcorn, it won't calculate steps accurately and therefore calories burned will not be accurate. It's going back to the store tomorrow to get replaced by a pedometer until the technology catches up. ***** Update 5/7/2013 ***** This morning, my wife asked me to return her Flex. The bands are really stiff and she still can't get it to latch on her own (it's a push fit). She's also decided she doesn't care for the way it looks. In fairness, I opened a support case with Fitbit regarding the device's accuracy. The reply; "...Like all Fitbit devices, Flex is designed specifically for step-based activities like walking and running, though it will still give you credit for other fitness activities to present a full picture of your overall health. You can manually log activities that Flex won't track well (like cycling or yoga) from your Fitbit account if you'd like a more accurate calorie and distance summary from your Flex." Fitbit is acknowledging that it's not accurate when you keep it on all the time. This is consistent with what I found during testing; works great for tracking walking or running, not so great elsewhere.