By now everyone is familiar with devices that you wear to track your physiological functions in order to monitor and track your energy levels and outputs. The most common devices are the ones you wear on on your wrist.

Here are the main features of wearable fitness devices:

• Step counter: Activity trackers not only count the steps you take, but they also use accelerometers and altimeters to calculate your overall distance traveled.

• Heart monitor: Many devices have special sensors that can tell you your heart rate.

• Calorie monitor and counter: Working with the step counter, this feature can tell you how many calories you’ve burned while walking. You can also track how many calories you’ve consumed throughout the day.

• Exercise tracker: You can use the device to track how much exercise you do each day and learn how many calories you burn while exercising.

• Sleep monitor: This feature not only tracks how much sleep you get, but also tells you how restful your sleep is.

• Goal setting: You can set personal fitness and health goals and receive notifications when you achieve (and more importantly when you don’t achieve) those goals.

• Connectivity: These devices can connect to apps on your smartphone or the Internet to track your long-term progress. You can also share your fitness data online and interact with others.