Heart Rate

What is a heart rate? 
A heart rate is the rate that the heart beats. Doctors can quickly check your heart rate as a quick evaluation of your health. It is determined by the number of beats per minute. When you age your heart rate slows down gradually.
What is the normal heart rate for someone your age?
By the age of 12 or 13 your heart rate would be at 70 - 120 beats per minute. This number increases during exercise.
When you exercise your heart rate...
When you exercise your heart rate rises greatly, when you relax it decreases back to normal.
How does your heart rate change as you get older?
Your heart rate gradually slows down as you increase in age, therefore making it harder to exercise
How can you measure your heart rate?
You can check your pulse by holding two fingers on the back of your wrist after exercising you count how many beats you can feel. Count the beats and after a minute the number you get to is the rate your heart is going.