Heart Rate

Heart rate refers to how many times your heart beats a relaxes per minute. People's heart rates vary considerably depending on what they are doing, there levels of fitness, the medications they are on and their age. 

Your resting heart rate for a twelve year old is 75-100 beats per minute. The maximum healthy heart rate you should have is 200 subtract your age, so 188 beats per minute for a twelve year old.

If you are 82 or something around there your heart rate will be around 72 beats per minute where as if you were 4 or 5years old your heart rate would be about 100-140 beats per  minute. As you get older your mussels slow down so your heart rate wont be as fast. 

To find your heart rate you put two fingers beside your neck or put your fingers on your wrist and time your heart rate for one minute.