What is an Activity Tracker?

An activity tracker is a small, wearable, wireless sensor that as its name implies, “tracks” your actions throughout the day. A tracker can measure how many steps and how far you walk, how many calories you burn, and your “active” versus “inactive” minutes. Some activity trackers monitor how much and how well you sleep.

Trackers can be placed in a pocket or clipped onto a shoe or an article of clothing, like a belt, waistband or bra, or worn on a wristband, armband or as a pendant around the neck. Regardless of where it’s worn, all trackers pretty much rely on the same basic technology –  an accelerometer, which is a big word for a tiny motion detector. The tracker then calculates steps and calories burned based on the speed of movement . Most of these devices are smart enough to detect when you’re driving in a car, or riding on a train, and don’t factor the distance traveled as a passenger into their count. (Mishaps do occur: One of our reviewers noted that his tracker logged 10,000 steps for a motorcycle ride!)

Some brands of trackers also contain an altimeter which measures altitude and can compute stairs. Most trackers work best when you’re engaged in activities that involve your two feet touching the ground, like running or walking, but some are sophisticated enough to follow other forms of activity, like riding a bike or using an elliptical machine. A few are waterproof and can be worn when swimming.

Unlike old school pedometers that merely counted steps or calories burned, and left it up to you to record your progress, today’s activity trackers can automatically send your data to an impartial third party – the internet. Your information is stored in the “cloud” and can be accessed from anywhere, anytime on your computer, tablet or smart phone. This not only provides an easier way to track your progress over time, but it also keeps you honest. Unlike a self-reported diary, an automated activity tracker makes it impossible to “fudge” your data or “forget” to record your numbers on a bad day.

And, you can easily share your information, in real time, with anyone in your social network. You can email it to your doctor; post it on Facebook or even tweet about it.  By sharing your results, your friends can provide motivation and moral support, and even forge friendly competition to keep you on ‘track.’  Of course, you can also keep your data absolutely private, the choice is yours.