Normal vital signs change from infancy to adulthood, including pulse rate, which typically mirrors the heart rate. Due to anatomical differences, what is normal for one age group could be abnormal for another. Normal pulse rate changes substantially from infancy to middle childhood. By age 12, the normal pulse rate approximates that of an adult.
Normal Pulse Rates Vary
A child's normal pulse rate varies within a relatively wide range throughout the day because it changes in response to the body's needs. For example, a child's pulse rate typically increases immediately after eating, and is higher while awake than asleep. Although there is slight variation from one reference to another, a normal resting pulse rate range for a 12-year-old is typically 60 to 100 beats per minute, with an average of about 85.
Effect of Exercise
Regular exercise is important to keep a child's heart and body healthy. To benefit the heart, exercise must be vigorous enough to push the pulse rate into a specific target range. For example, a 12-year-old with a resting pulse rate of 75 will derive heart benefits from a pulse rate of approximately 135 to 180 beats per minute during exercise. During extremely strenuous activity, the pulse rate sometimes rises even higher. The target pulse rate range during exercise varies slightly, based on a child's resting heart rate.
Warnings and Precautions
A resting pulse rate greater than 100 or less than 60 could be cause for concern in a 12-year-old. Pain, fever, dehydration, anemia, accidental medication overdose and many other factors and conditions can affect pulse rate. If you are concerned that your child might have an abnormal pulse rate, talk with your doctor. Seek emergency medical care if your child has an abnormal pulse rate with breathing difficulty, lightheadedness, dizziness or fainting.
Reviewed and revised by: Tina M. St. John, M.D.