The device turns or slides on the wrist

Why this is a real problem

A device that rotates ends up under the wrist, where the skin is thin, the bone close and circulation different. The sensor loses the firm contact it needs, and the data becomes unusable: jagged heart rate, gaps in overnight tracking, incoherent recovery.

So this is not a comfort detail. A device that moves is a device that lies.

Cause 1: the fit

Obvious, but rule it out first. One finger should pass between strap and wrist, not two. Under exertion the forearm swells: what held at rest can start turning mid-session.

Cause 2: position

A markedly conical wrist — narrow near the hand, wider towards the elbow — makes any band slide down, whatever the fit. The answer is not to tighten but to move up: a few centimetres towards the forearm finds a more cylindrical section. See: where to wear your WHOOP.

Cause 3: the band is finished

If the device moves with the clip set as tight as it goes, the elastic has given up. No adjustment rescues a weave that no longer returns to length. It is the first of the three end-of-life signs. See: what wears a weave.

Cause 4: the device is not locked

Rare, but it shows up after a band change. A half-seated module has play in its housing: it is not the band turning, it is the device floating inside it. Pull gently along its axis; if it moves, it is not in place. See: changing your band.

The wrong reflex

Tightening one more notch every time it slips. You end up restricting circulation, marking the skin and accelerating wear on the weave — without addressing the cause, which is nearly always position or the age of the band.

A weave that holds

A strap that keeps its tension solves half the problem. Already Late Navy and Denim take up one notch and stay there.