A study conducted by researchers at the University of Waterloo, Canada shows the Apple Watch can accurately predict stress levels (via MyHealthyApple). The researchers found that the Apple Watch Series 6’s ECG sensor data could be used to develop an accurate stress prediction tool.
Currently, Apple does not provide a Stress score feature on its Apple Watch platform. However, other wearable devices from Samsung, Fitbit, and Garmin have offered Stress monitoring for some time now.
Participants in the study were given an iPhone 7 running iOS 15.0 and an Apple Watch Series 6 with the Apple Watch ECG app (WatchOS 8.3) for two weeks.
The researchers found a connection between ECG data, including heart acceleration and deceleration capacity, and participants’ reported stress levels at the time the readings were taken. Machine learning algorithms were then developed using this information to create a prediction model.
The researchers found that “In general, the “stress” models had a high level of precision but lower recall. The ‘no stress’ models performed generally well with a recall typically above 60%. Considering the ultra-short duration of the ECG measurements performed here compared to the standard, as well as the nature of real-life measurements, the results presented were quite promising.”
The researchers say that since the wearable device collects additional health information such as sleep and activity information, more data points could also be included in stress models to increase their predictive accuracy.