Over the course of just a few years, activity trackers evolved from simple mechanical step-counters into sophisticated digital devices that track your activity, monitor your heart rate, and even evaluate the quality of your sleep.
Millions of people are wearing these devices all day every day, but the technologies have evolved so quickly that we don’t have much long-term data about their use. So what’s the truth? Is it safe to wear a Fitbit all the time? Let’s find out.
What is Fitbit?
Although we all know what a Fitbit is, it’s less clear what the Fitbit company is. It was founded in 2007, and in 2015 announced a transition from being a “consumer electronics company” to a “digital healthcare company.”
The problem is, by marketing their products as health care products, it’s natural for consumers to hold the company and its products to a higher standard. When a person chooses a Fitbit to help them pursue a health-related goal, the accuracy of the device and its marketing claims becomes much more important.
This idea was recently tested in Brickman, et al. v. Fitbit, Inc., where a class action lawsuit was filed over inaccuracies in Fitbit’s heart rate and sleep monitoring. Consumers felt that they were misled, since they paid more for Fitbits with heartrate and sleep tracking features, and yet the devices were inaccurate and unreliable.
An independent study on behalf of the plaintiffs found that Fitbits were off by an average of 20 beats per minute during exercise, which may be inaccurate enough to pose a health risk. Fitbit settled this lawsuit in early 2019, but filed an appeal in April 2020.
Are Fitbits Safe?
Fitbit safety concerns typically fall into two major categories:
Having a reaction to the Fitbit wristband is so common that it’s known as “Fitbit Rash.” Wearing a Fitbit 24/7 may result in irritation and dermatitis at the site of the wristband. This may be due to sensitivity to some of the materials that make up the Fitbit, or due to rubbing and chafing from wearing the band, or some combination of factors as soap, sweat, or debris may become lodged between the skin and the wristband and irritate the skin.
For those people experiencing Fitbit rash, it’s important to loosen and remove the Fitbit often, keep the Fitbit and the skin beneath it clean, and heal and protect the skin. Fitbit rash may also be caused by an allergy to nickel, which can be determined with the help of a dermatologist.
Many people are concerned about constant exposure to the radio and electromagnetic frequencies and radiation emitted by a Fitbit. This kind of exposure is measured by the Specific Absorption Rate, or SAR.
The SAR measures how much energy is absorbed by the human body, and it’s used to measure radio frequencies, electromagnetic fields, ultrasounds, and non-ionizing radiation. It is expressed as the amount of exposure per mass of body weight. It probably goes without saying that this can be an extremely controversial subject, as people are concerned about this kind of exposure from mobile phones, from cell phone towers, from wearable devices, and more.
Many people recommend not using any wearable devices, to avoid exposure to RF and EMF waves. Currently, the FCC limits the SAR from mobile phones to 1.6 watts/kilogram of mass, and requires manufacturers of all mobile devices to conduct rigorous testing of their SAR and make the results public.
For example, here is the UL certification for the Fitbit Versa, tested in 2018. According to this test, the Fitbit passed FCC limits, with just 0.055 watts of RF exposure per kilogram.
The truth is, we simply don’t have the longitudinal studies right now to determine whether wearing a Fitbit 24/7, year in year out, may have long term negative health effects. According to the standards and guidelines we have now, these are safe devices and there is no reason to not wear them 24/7 if you choose.
If your Fitbit causes skin irritation, take it off for a few days and clean and disinfect it thoroughly, and care for the skin of your wrist. Put it on again and take care of the area and see if the irritation continues. If you have Fitbit Rash but keep wanting to wear the device, consult with a doctor or dermatologist to find the right solution for you.