How Does Your WATCH Read Your BODY?

How does a smartwatch read your heart, oxygen levels, sleep, and steps? We crack open the science, compare its readings with medical devices, spot veins with infrared, and even try to fool it with a water-filled tube. The results are surprising—and your step counter might be easier to trick than you think! Subscribe for more curious experiments. Tell us in the comments what you liked most about the video! #Smartwatch #Science #Technology #Health #Experiments 👉 This channel was created in collaboration with    / @manualdomundo   0:00 - Smartwatch Features and Health Tracking 2:29 - Workout Tracking and Heart Rate Data 4:46 - How Heart Rate Sensors Work 10:33 - Blood Oxygen and Optical Measurement 15:02 - Seeing Veins with Infrared Light 16:59 - Trying to Trick the Watch 18:27 - GPS, Steps, and Motion Sensors 22:49 - What Smartwatch Metrics Can Tell You