Your Fitness Tracker May Be Lying To You About Something Really Important

Feeling pretty great about the 600 calories you just burned during your 45-minute yoga class?

Hate to break it to you, but you probably burned less than that.

Even when you enter your weight and age, most exercise apps -- and even some expensive fitness trackers -- inaccurately estimate how many calories you actually burn during exercise by as much as 20 percent, according to Vox.

This is because there's a lot to take into consideration when it comes to calorie burning -- heart rate, breathing and fitness level, for example.

Sherry Pagoto, cofounder of the UMass Center for mHealth and Social Media, tells Vox,

A highly trained runner who is 120 pounds likely burns less calories than a newbie who is 120 pounds and running the same distance and pace. This will bear out in their heart rate data -- the more conditioned one gets, the lower the heart rate during the same activity, and the fewer calories burned.

Still, it's not like fitness apps and trackers have it all wrong. If you're trying to lose weight, Pagoto suggests going with a more conservative calorie estimate if you're given a calorie range.

Forbes contributor Dr. Robert Pearl suggests,

Pay attention to both sides of the equation.

In other words, don't just look at how many calories you burned on your morning jog; accurately log what you eat every day as well. As the same article points out, we often underestimate how many calories we actually eat. Don't let that happen to you!

If you want to invest in a more high-quality fitness tracker, here are the best ones. Just be prepared to fork over a hefty chunk of change.

Citations: Why you shouldn't trust the calorie estimates on your fitness tracker (Vox), Can Your Wearable Device Really Help You Lose Weight And Get Fit? (Forbes), Best fitness trackers 2015: Jawbone, Misfit, Fitbit, Garmin and more (Wareable)