These high-tech wristbands use motion sensors to time and record our movements in everyday life and during sports. They calculate calorie consumption, provide information about training intensity and encourage regular exercise. They can determine sleep phases so precisely that an integrated wake-up function wakes the wearer at the optimum time, thus allowing a well-rested start to the day. The fitness wristbands are generally compatible with smartphones, use their GPS function for more accurate movement measurement, provide information about e-mails or calls directly on the wrist and allow fitness data to be conveniently shared on social platforms. Some activity trackers also have a wrist pulse monitor or can be combined with a heart rate monitor belt.