Fitbit tracks activity, day and night

Turns out, I wake up about eight times a night.

But I'm getting more sleep than I thought. About seven hours a night.

And turns out my recent Jazzercise classes have burned more calories than I originally thought — about 400 in a 60-minute class.

And I see now that choosing to walk up four flights of stairs instead of taking the elevator to the marketing department is a great habit. I might be sweaty and huffing when I arrive for a meeting, but choosing that route really does scorch calories.

How do I know all this stuff?

For the last few weeks, I've worn a key-sized wireless computer on my bra strap. It's called a Fitbit, and it tracked my steps, activity level, calories burned and distance walked. At night I moved it to a wrist sleeve, and it monitored my sleep — what time I got into bed, how many minutes it took to fall asleep, and precisely how many times I woke up and how long I was awake.

Throughout the day, it sends the information collected to my computer, where I can view my real-time stats at www.fitbit.com.

The Fitbit is one of several computerized personal trainers on the market. Others are the BobyBugg ($249), GoWear Fit ($199), and the Adidas MiCoach ($125.99). These are products meant to help people understand just how active they really are. They're basically pedometers on speed.

Fitbit co-founder Eric Friedman said the Fitbit was made with average people in mind, not high-end athletes. They retail for $99, at Fitbit.com.

"We view the Fitbit as the lazy person's way" of tracking their activity, Friedman says. "It's like a mini personal trainer. Some people use it as their conscience, because it's around all the time."

The Fitbit can change the way you view yourself and your fitness habits. It reinforced how much the little things, like a 10-minute walk, count. I could see activities like chasing my son around the house (his favorite game), walking through the mall and taking the stairs did add up, moving my calorie count up sometimes by the hundreds.

On the companion Web site, besides checking out your daily activity, you can log your food intake, so you can directly compare calories going in and going out.