I went to the FitBit website and decided that the FitBit Flex Wireless looks pretty cool because it's on a wrist band, tracks sleep quality, has a silent wake alarm and blinky lights. I know my sleep is lousy though, so I didn't get one, but I did notice that the FitBits are compatible with the RunKeeper website. I've recently (and independently) started using RunKeeper with my phone to track my exercise - mostly walking at the moment.
I expect that Truthtable would be concerned about the limitations of GPS precision when walking, and I do appreciate the potential for that concern. However, I've empirically determined that it works well, truthfully.
As far as any concerns about the FitBit go - I don't own one. Regardless, I do understand a thing or two about precision. There is so much variability in daily activity, that being concerned about even 10 or 20% error is really akin to measuring with a micrometer, marking with chalk and cutting with an axe. Given that, I'd have to truthfully say that Max's analysis of the FitBit is very helpful and totally, truthfully, appropriate.
What's more important is consistency. Try to position and measure the same way all the time as much as possible. Then you can compare relative to yourself. But, what? You say? You won't be able to compare yourself to anyone else?. Sorry, but, truthfully, you can't do that anyway with much precision no matter what the tool.
The bottom line is that in each case (Fitbit clipped to shirt pocket, short center, pants side picket, and pants center), there was some amount of error in the step count. I found this to be a little disquieting. I'm a bit of an obsessive compulsive when it comes to things like this. You can call me old-fashioned if you will, but I do like my numbers to add up to the correct value.
I don't think you should monitor yor blood pressure then. My cardiologist tells me that he hates engineers as patients because they demand a level of accuracy that medicine cannot provide. My home blood pressure monitor takes 3 sequential readings separated by 30 second intervals. The cuff doesn't move. I am motionless. Yet the blood pressure can vary by 30mmHg across the 3 readings which it then averages. I can get a systolic reading varying from 150 to 120mmHg- from dangerous to normal. When am I supposed to worry (in increase by pressure even further)?
I love my FitBit Zip and have been wearing it every waking hour for about 10 months now. It is indeed very motivational. Like Max said, I find myself going out of my way just to "get more steps." I also like that it integrates well with MyFitnessPal, which I use to track my exercise & food intake. That app is clever enough to subtract out the calories burned when you wear your FitBit while exercising, so there is no double counting.
I agree that consistency is more important than absolute accuracy. I always wear mine on my hip, and the few times I have checked it against a count of my actual steps, it has been within 1 step in 100. I'm perfectly happy with a 1% error.
For the ultimate gadget freak who is into monitoring diet & exercise, FitBit also makes a scale that has built-in WiFi, so your weight is automatically logged to your FitBit account. Of course, the scale is also clever enough to know whether it is me or my wife that has just stepped on it :)
@Max: "Consider the first test shown above in which the Fitbit was attached to my shirt pocket. While walking on the treadmill, the Fitbit reported far fewer steps than I actually took"
The result is clear: the Zipbit is not Hawaiian-Shirt proof!!
The Zipbit webpage indicates that you must attach it close --nearly sticked-- to your body. As you wear loose Hawaiian shirt, as you point too the 3-axis accelerometer is not properly registering your actual movement.
Maybe you should try to wrap it in your chest with an elastic band -- or even adhesive tape, but I must recognize that I'm so furry for doing that test without the pain ;-)
Modern world makes everyone busy and most of us inevitably sit most of the day. Yet, we all know that exercise is the best way to keep you health. If this apply to you, you definitely will like to quantify your exercise level as much as possible. No doubt if you can run for an hour or go to gym for an hour or so, you will get a better health index. Nonetheless, every step counts when your day is pretty much filled up with work and family. So, fitbit and Up by Jawbone come into the picture. It gives up incentive to walk/ run. It quantifies every extra steps we have made. To me, this is a device making me eager to walk.
No doubt, like most measurement tools, there is a margin of error. Pedometer has been around of 10, if not 20, years. I am sure it has gone through multiple version to make to the accuracy today. Thanks to the article, I now understand better where it shall be to get the best out of it. Wonderful work, Max!
As Benson said, pedometer overcomes certain limitation of GPS. Unargueably, pedometer doesn't really give you the most accurate distance in terms of miles or kilometers. Yet, GPS could overcome it. I wonder why the product with the combination of both has not come into market yet.
@Duane:What's more important is consistency. Try to position and measure the same way all the time as much as possible. Then you can compare relative to yourself. But, what? You say? You won't be able to compare yourself to anyone else?
I agree that consistency is important, so if you were it in the same place and do the same exercise each day, it's useful for comparing yourself to yourself.
Stiill and all -- I prefer to know that my count of say 3000 steps is as close as possible to reality if only for my onw peace of mind (obsessive compulsive, remember).
And remember that the Fitbit gave accurate results irrespective of where it was clipped when I was in sneakers walking on a hard surface (worst case was 1 step error out of 100 -- and that was measured over 100 steps, so there could be a glitch in my count starting and stopping -- I woudl not be supprized to find the error fell to 1 out of 1000 steps if I had performed the test over 1000 steps).
The problem was on the treadmill -- if I were competing with others, I would ask them to wear their Fitbits on the center of their pants while on a treadmill so that we could be reasonably sure we were counting much the same thing...
Make sure to take any wearable electronics off your clothes before you throw them in the washing machine.
I just finished a 30 min walk on the treadmill in my bedroom with my Fitbit clipped to my pajama pants -- then I threw them into the washing machine with a bunch of other clothes before heading off to the shower.
The washing machine had just started up when I thought to myself "Oh dearie, dearie me!" (or words to that effect) and ran back and stopped the machine. Fortunately the pants with the Fitbit were on top of the pile and it hadn't been submerged yet ... phew!
Blog Make a Frequency Plan Tom Burke 17 comments When designing a printed circuit board, you should develop a frequency plan, something that can be easily overlooked. A frequency plan should be one of your first steps ...