Question 1

Is the data on the watch itself?

Accepted Answer

Only recently: the watch is a relay with limited storage, holding recent readings until they sync (§4). The fuller history is cached in the companion app on the paired phone, and the complete, detailed, long-term record lives in the manufacturer's cloud, which is usually the real source (§3, Example 2). So the account, not the watch, is what you preserve and collect first; extracting the watch alone yields a fragment.

Question 2

How accurate is fitness-tracker data?

Accepted Answer

Indicative, not clinical: consumer sensors estimate, heart rate optically, sleep from movement, steps from motion, and can be wrong (§6). That does not make the data useless; it makes it evidence to be presented as indicative and corroborated against other sources, not asserted as medical measurement. Its accuracy and any gaps are explained honestly, so the court knows the weight it can bear.

Question 3

Does the watch prove who was doing the activity?

Accepted Answer

No, only that whoever was wearing it did (§6, Example 3). Usually that is the owner, but not invariably, so attribution requires corroboration, the paired phone's location, messages, other evidence, and the finding is stated at the level the data supports. The wearable records a body's activity; identifying whose body, and where, comes from the corroborating sources beside it.

Question 4

Can we get the other side's wearable data?

Accepted Answer

By the proper routes: preservation and disclosure of the relevant records, or a data export from the account, and for a party's own data a subject-access request is often a lawful, proportionate route (§4). Because this is special-category health data, collection is scoped to the relevant metrics and period and minimised, and handled with heightened care (§7). It is obtained law full y and proportionately, not scraped indiscriminately.

Question 5

The device was reset. Is the data gone?

Accepted Answer

Usually not: a factory reset clears the watch, but the history has already synced to the cloud, and the account, preserved and collected law full y, holds the full record untouched by the reset (Example 2, §8). Resetting the device does not reset the account. And a reset performed after the duty to preserve arose may itself be a spoliation point (§10). The wiped watch is rarely the end of the record.

Question 6

Is wearable health data specially protected?

Accepted Answer

Yes: activity, heart-rate and sleep data are special-category health data under the UK GDPR, among the most sensitive personal data, so their collection, disclosure and use carry heightened duties, a lawful basis, data minimisation and security (§7). In practice this means scoping to the relevant period and metrics, protecting the intimate data beyond the issue, and handling the whole collection with the care that health information demands. cflab. u k · e-disc ove r y. u k ©2026 Computer Forensics Lab Ltd ·cflab.uk ·e-discovery.uk ·info@cflab.uk ·+44 (0)20 7164 6915 Page 15 of 17

Wearables And Fitness Tracker Forensics