Do you own a Fitbit? If so, you may not be getting accurate data according to a recent study.

California State Polytechnic University, Pomona researchers ran tests on the heart rates of 43 healthy adults wearing Fitbit devices equipped with their PurePulse heart rate monitors on each wrist.

Researchers then hooked up a BioHarness device that gave them an electrocardiogram to compare the heart's rhythm against the information provided by the Fitbit devices.

Comparative results from rest and exercise — including jump rope, treadmills, outdoor jogging and stair climbing — showed that the Fitbit devices miscalculated heart rates by up to 20 beats per minute on average during more intensive workouts.

The study found that Fitbit's PurePulse Trackers miscalculated heart rates "by up to 20 beats per minute on average" thus "do not accurately measure a user's heart rate" and "cannot be used to provide a meaningful estimate of a user's heart rate."

Eric Thayer, Getty Images

It should be noted the study was conducted by the law firm behind the class action lawsuit against Fitbit and their three devices that use the PurePulse heart monitor.

Fitbit has stated that what the attorneys call a 'study' is biased and lacking scientific backing when it comes to its methodology.

It was paid for by plaintiffs' lawyers who are suing Fitbit, and was conducted with a consumer-grade electrocardiogram — not a true clinical device, as implied by the plaintiffs' lawyers. Furthermore, there is no evidence the device used in the purported 'study' was tested for accuracy.

Fitbit claims their team "rigorously researched and developed" PurePulse technology for three years before it was even introduced to consumers and continue to run studies to improve the feature.

Other studies have shown Fitbit's Charge HR had heart errors of 14 percent (20 or 30 beats) which is very dangerous for people with high risk when it comes to heart disease.

In response to one study, Fitbit did state that their devices

are designed to provide meaningful data to our users to help them reach their health and fitness goals, and are not intended to be scientific or medical devices.

Do you think Fitbit products are worth the money if they can't guarantee accurate data?

[via NBC]