Lieff Cabraser Team Sues Fitbit Over Heart Rate Readings

Lieff Cabraser Team Sues Fitbit Over Heart Rate Readings

SAN FRANCISCO — A team from Lieff Cabraser Heimann & Bernstein is aiming for the jugular in a new suit against Fitbit Inc., claiming the company’s wearable heart rate monitors don’t work as advertised.

Fitbit’s Charge HR and Surge devices, which boast technology that monitors users’ heart rates during exercise, consistently report “wildly inaccurate” readings, according to a class action complaint filed Tuesday in the Northern District of California. Fitbit promoted the new “PurePulse” technology with slogans such as “every beat counts” and “know your heart,” and pictures of athletes using the devices during workouts.

“But the representation is false,” according to the plaintiffs team led by Lieff partners Elizabeth Cabraser in San Francisco and Jonathan Selbin in New York. “Far from ‘counting every beat,’ the PurePulse trackers do not and cannot consistently and accurately record wearers’ heart rates during the intense physical activity for which Fitbit expressly markets them.”

In an emailed statement, a Fitbit representative wrote the company stands behind its heart rate technology and plans to vigorously defend the lawsuit.

“PurePulse provides better overall heart rate tracking than cardio machines at the gym, as it tracks your heart rate continuously—even while you’re not at the gym or working out,” the representative wrote. “But it’s also important to note that Fitbit trackers 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.”

San Francisco-based Fitbit sells sporty wristbands that offer step counting, distance calculating, calorie calculating and sleep monitoring functions. When the company added heart rate tracking to its products in 2014, it eliminated the chest straps employed by other heart rate monitors that could be uncomfortable or distracting, according to the complaint. Plaintiffs say they paid more for the new feature. The Charge HR sells for about $150, plaintiffs report, as compared to $100 for the Charge without a heart rate monitor.

Three users named as plaintiffs in the suit claim the devices underreported their exercising heart rates. A Wisconsin man who was training for a marathon says his Surge was often off as much as 15 to 25 beats per minute when compared to his chest-strap monitor. The complaint also includes snippets of customer reviews from, which call the heart rate monitors “useless,” and a “huge disappointment,” and compare it to “the proverbial broken clock which is 100 percent accurate twice a day.”

The plaintiffs lawyers say expert analysis corroborates the customer complaints. A cardiologist testing the Fitbit devices against an electrocardiogram found the Fitbit devices were off by an average of 24 beats per minute, with some readings off by as much as 75 beats, according to the complaint.

Plaintiffs lawyers seek to represent a national class of customers who bought Fitbit heart rate monitors, and subclasses of California, Colorado and Wisconsin customers. The legal team also includes Oregon solo Robert Klonoff

The suit pre-emptively challenges Fitbit’s arbitration agreement and class action ban, which appears on the company’s website. Customers who buy the devices from a brick-and-mortar store or through a third-party online retailer aren’t exposed to the arbitration agreement until they take their devices home and try to register them online, according to the complaint. Such registration is necessary before the devices will function, the lawyers wrote.

The arbitration agreement is “unconscionable, invalid, and unenforceable,” the lawyers wrote. “It is also an unfair and deceptive trade practice in its own right.

Morrison & Foerster represents Fitbit in separate litigation claiming that its trackers’ sleep monitoring functions don’t perform as promised.

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