Smartwatches misread stress, study finds

A study shows smartwatches cannot reliably measure stress and may confuse excitement with stress.

Smartwatches misread stress, study finds

Researchers followed 800 young adults who wore Garmin vivosmart 4 watches for three months. Participants reported stress, fatigue and sleep four times daily, creating a dataset that paired self reports with wearable readings. The study found almost no relationship between self reported stress and the watch's stress scores. In many cases the watch flagged stress when the user reported calm or happiness, and vice versa.

Fatigue, called body battery by Garmin, showed a small link to the wearable data but the overall connection remained weak. The sleep measure had a stronger relation, with two thirds of participants showing alignment between sleep data and self reports. The researchers say wearables track signals that do not map directly to mood, and that hair standing on end can signal both anxiety and excitement. The work aims to build an early warning system for depression, but experts warn that consumer devices are not medical tools and must be interpreted in context.

The findings challenge the idea that wearables can replace clinical insight. For everyday users, the result suggests a smartwatch should not be treated as a stand in for stress or mood. For researchers, the study highlights the difficulty of isolating emotion from heart rate signals and points to the need for multi modal data and careful interpretation.

Industry implications include clearer cautions in product materials and better data fusion with sleep and activity data. The study also raises questions about privacy and how much users should rely on device readouts for mental health self care. Wearables can help spot patterns over time, but they do not deliver a definitive read on how a person feels in the moment.

Highlights

The next step is honest appraisal and better design.