I’ve been hearing about a number of devices and smartphone apps recently that track your fitness and activity levels. Two examples are the Fitbit and DigiFit and I’m sure there are many more. The concept behind these devices is pretty simple. You wear a simple device on your pants, shirt, bra or wrist and it keeps track of your levels of activity through the day.

I read one thing that described these as a pedometer on steroids. That’s a generally fair assessment, although these devices are becoming much more advanced than a simple pedometer. For example, most pedometers try and tell you how many calories you burn. To do so, they basically take your number of steps and multiply it with an average number of calories per step. There’s no need to explain why this isn’t the most accurate of data.

Instead of this simple calorie calculation, the latest devices are using a built in accelerometer to be able to calculate movement and calorie burn more accurately. Certainly this still isn’t an exact science, but it is a really interesting set of data and more accurate than using some crazy average. It’s always bothered me when treadmills tried to tell me how many calories I’ve burned. At least this gets us a little closer to reality since it’s measuring movement on a more granular level.

These devices also have started to come with built in sleep sensors. Tracking how and when you sleep is another interesting set of data. I’m not sure we even know how valuable this data could be, but I’m happy that we’re starting to collect the data so we can’t start working on projects that will evaluate how to best use the data.

Of course, one of the real keys to these devices is that they easily sync with a website online. The ones I saw will automatically sync if you’re within 15 feet of the docking station. I assume this is using some sort of bluetooth communication, but won’t be surprised if near field communication takes off and makes this syncing of your fitness and activity data even better.

Then, the cool part is that all of your fitness and activity data is available on your iPhone or Android smartphone or on the web. For a stats junkie like me (and most people that I know) this is really cool. In fact, I think we’re just at the beginning of deploying various devices that track our health data. I can easily see us tracking blood sugar levels, cholesterol, blood pressure and many other levels. Then, the implications for healthcare become even more interesting.