How accurate is the Whoop band at tracking sleep?

The Whoop band is considered to be one of the more precise consumer-grade sleep trackers available on the market. It employs a combination of heart rate monitoring, heart rate variability (HRV), ambient temperature, and motion detection through an accelerometer to track sleep patterns and stages including light, deep, and REM sleep. Several studies and user testimonials have suggested that its accuracy is relatively high when compared to polysomnography, which is the gold standard for sleep measurement used in clinical settings. However, like all wearables, it may not always be 100% accurate due to various factors such as device placement or abnormal sleep conditions. Despite this, users can generally rely on Whoop for a good estimation of their sleep duration and quality, making it a useful tool for athletes and health-conscious individuals who want to monitor their recovery and performance.