Study Finds Smartwatch Stress Sensors Are Often Inaccurate and Misleading

A recent study conducted by researchers at Leiden University in the Netherlands has found that stress sensors in smartwatches and similar devices are frequently inaccurate. The study, published in the *Journal of Psychopathology and Clinical Science*, involved 800 young adults using the same Garmin Vivosmart 4 smartwatch model. Participants provided self-reports on their stress and fatigue levels four times a day, which were then compared with the data generated by the wearables. The researchers found a near-zero correlation between the smartwatch data and users’ reports, indicating that the devices often misinterpret real emotional states. The study also highlighted that the smartwatches could mistake physical activity, excitement, or even sexual activity for stress, leading to misleading results. While Garmin’s Body Battery feature, which tracks physical fatigue, was somewhat more reliable, stress indicators were still far from accurate. The best performance came from the sleep tracking feature, which was able to differentiate between a good and bad night’s sleep in about two-thirds of cases. The researchers noted that as wearable technology evolves, the accuracy of these sensors could improve, suggesting that newer models like the Garmin Vivosmart 5 or the latest Apple Watch could yield better results. However, for now, users should remain cautious when relying on their smartwatches to track stress and fatigue.