Before you buy a fitness tracker: reading health claims and data practices

How it works

Most wrist trackers do their measuring with two kinds of sensor. A small motion sensor feels how your arm moves. Steps are not counted directly: the device guesses them from movement patterns, so pushing a stroller or gripping a handlebar can throw the count off. Sleep works the same way. It is inferred from how still you are, often combined with your pulse, not measured in your brain.

Heart rate usually comes from lights on the back of the case that shine into your skin. The sensor reads how much light returns, which shifts as blood flows. That is an estimate of your pulse, and it can drift when the band is loose, when you move a lot, or when skin, cold or ink changes how light behaves. Anything more advanced is a calculation layered on those same signals.

That is why the regulatory label matters. In the United States, most trackers are sold under what the FDA calls its general wellness approach. The agency reissued its guidance for low risk devices in January 2026 and covers products that promote a healthy lifestyle, which is where a step counter or sleep tracker usually sits. See the FDA page on the guidance.

The line between wellness and medical is drawn by what the product claims. According to the Congressional Research Service, a wellness wearable should not diagnose or treat disease, should not stand in for a cleared device, and should have validated clinical-like values. Law firm Covington adds that a wearable drops out of the wellness category if it shows clinical-style values that are not validated. Read the CRS summary and Covington's note. The plain takeaway: a number on a screen does not mean the device went through medical review.

What matters

Some of what a box shows is marketing. A few things are checkable.

Claims wording. Per Covington, wellness wearables cannot claim to replace an FDA-cleared device, or claim clinical equivalence, accuracy or medical grade. If a wellness tracker's listing uses those phrases, look closer. A wellness wearable may suggest that seeing a healthcare professional could help, but it should not name diseases or label a reading abnormal.

Which metrics the maker documents. Open the maker's spec sheet or help pages. Does it list each metric, say how it is measured, and say which are estimates? A metric with no explanation is a number you cannot judge.

How battery life is stated. Look for the conditions behind the figure: which features were on, and whether it is a best case. Then check whether the maker says the battery can be serviced or replaced. A fading battery is what usually ends a wrist device's life.

What needs a phone or a subscription. Find out whether the tracker works alone, whether history and trends sit behind a paid plan, and whether the features shown in the ad are all included.

Data practices. The FTC treats health information broadly: anything that conveys or lets someone infer something about your health, including location or purchase data. It also says companies should not falsely call themselves 'HIPAA Compliant', 'HIPAA Secure' or 'HIPAA Certified', and should not bury key facts in privacy policies where few people read. Check the privacy settings before you make an account. The FTC's page on consumer health information lays this out.

What it costs

The sticker price is the first line of a longer bill. Here is a simple way to total it for the years you expect to keep the tracker:

• Purchase price
• plus subscription fee, multiplied by the months you will pay it
• plus battery service, if the maker offers it, and its fee
• plus replacement bands, since a band is worn and sweated on daily

Fill in each line from the maker's own pricing and terms, not from the ad. A cheaper tracker with a paid plan can end up costing more than a pricier one that works fully on its own. Also ask how long the maker says it will support the device and its app, and what happens to your history if you stop paying.

The fifth line is data. A cheap or free app may be paid for in another way. The FTC cites BetterHelp, GoodRx and Premom as cases showing that sharing health data for advertising without affirmative express consent may be unfair. So check whether the company shares data with advertisers and whether it asks you first. Treat a yes you did not give as a cost. See the FTC's health data guidance.

What protects you

Privacy. Many people assume HIPAA covers everything health related. The FTC says it covers most doctors' offices, hospitals and insurers, but much health information from monitoring technology falls outside it. That gap is where the FTC's Health Breach Notification Rule applies: it covers apps and connected devices that hold health information outside HIPAA. After a breach, the company must notify affected people and the FTC. A breach is not only a hack; it includes unauthorized disclosure, such as sharing health data with advertisers. Notices now focus on email and other electronic notice such as in-app messages, so keep a working email on the account. Companies that fail to comply face penalties. Details are in the FTC's rule basics and its blog on the update.

Separately, the FTC Act requires companies to honor their privacy promises and keep security appropriate to the data they hold, according to the FTC's health privacy page.

Warranty and returns. I could not cite an FTC warranty page for this edition, so I will not summarize its rules here. What you can do is get the written warranty and the store's return policy before you pay, and save a copy. Look for what the warranty covers (does it mention the battery or the band?), how long it lasts, and who handles a claim. Return windows and restocking terms are set by the seller, so ask for them in writing.

Recalls. Check before buying. A CPSC notice from 2018 recalled about 30,000 Provata activity tracker wristbands for overheating while worn or charging, with reports of burns to the wrist. The remedy was a free replacement. It is an example of why to search, not a statement about any current product. Read the CPSC notice. Federal law prohibits selling products under a CPSC-ordered or CPSC-consulted voluntary recall. If a recall remedy gives you trouble, use the CPSC's recall complaint form, and report unsafe products or injuries at SaferProducts.gov or the CPSC hotline.

What to ask

Put these to the seller, or look for answers in the maker's documents:

• Which readings are wellness estimates, and does the maker say any are validated?
• Does the packaging claim medical grade or clinical accuracy?
• What data does the device and app collect, including location, and is any shared with advertisers? Do I have to say yes first?
• Will a breach notice reach me by email? What does any HIPAA claim actually mean?
• What does it cost to keep it working: subscription, battery service, replacement bands?
• What does the warranty cover, and what is the store's return window?
• Has this model or maker appeared in a CPSC recall notice?