⌚ Smartwatches have evolved from basic step counters to powerful health companions — tracking your heart rate, stress levels, calories burned, and even blood pressure and sleep stages. But how exactly do they do it? Are they accurate? And which ...
In recent years, smartwatches have added a surprising feature to their list of abilities: tracking sleep. At first glance, it may seem a bit mysterious. After all, a watch can’t exactly tell you to count sheep or whisper, “Time for ...