Your Fitbit Is Lying To You

Devices that track your steps and calories are incredibly popular, but just how accurate are they?

I'm a runner. I have a Nike GPS watch and I've used it for the past 6 years to track my miles and calories. I enjoy running half and full marathons so training is important. I've done several accuracy tests including mapping out my run on Google before taking off so that I can compare when I finish. I've never put too much stock into the calorie counter but the mileage tracker is pretty close.

The calorie count is important to a lot of people though, but unfortunately it seems like that feature on these type of devices isn't very reliable.

NBC News ran the segment below on Thursday night comparing three different wearable fitness trackers.