Do You Know Your Target Heart Rate?

female woman running in the street
When you exercise, your body speeds up, and so does your heart as it works to meet your increased energy needs. But how much speeding-up of your heart is safe when you exercise? You need the answer to this
question in order to maximize your exercise benefits while not overworking your heart.

How do you figure out your target heart rate? How long do I need to work out after reaching it? What is a target heart rate?