Wearable fitness trackers monitor health metrics by utilizing various sensors to collect data on user activity, heart rate, sleep patterns, and more. These devices use accelerometers and gyroscopes to track movement and calculate metrics like steps taken and calories burned. Additionally, heart rate monitors provide real-time data about cardiovascular activity, while sleep trackers analyze sleep quality. This information is often synced with mobile applications, allowing users to visualize and assess their health goals. Overall, wearable fitness trackers encourage users to maintain healthy lifestyles by promoting awareness of their physical activity and wellness.