HOW FAST DOES YOUR HEART BEAT?

By: Rachel MayFebruary 9, 2010

STANDARD 2: SCIENTIFIC THINKING

Indicator 4.2.4: Use numerical data to describe and compare objects and events.

Taken from: http://dc.doe.in.gov/Standards/AcademicStandards/StandardSearch.aspx

Link to activity: http://www.indianastandardsresources.org/files/sci/sci_4_2_4.pdf

DEFINITIONS

Heart Beat: a complete cycle of cardiac muscle contraction and relaxation. (Mosby's Medical Dictionary, 8th edition. © 2009, Elsevier)

Heart Rate: the rate or tempo of heart contractions recorded in beats per minute. (Mosby's Dental Dictionary, 2nd edition. © 2008 Elsevier)

Pulse: the rhythmical dilation of arteries produced when blood is pumped outward by regular contractions of the heart, especially as palpated at the wrist or in the neck. (The American Heritage® Medical Dictionary Copyright © 2007)

BACKGROUND INFORMATION How does the heart beat? Before each beat, your

heart fills with blood. Then its muscle contracts to squirt the blood along. When the heart contracts, it squeezes — try squeezing your hand into a fist. That's sort of like what your heart does so it can squirt out the blood. Your heart does this all day and all night, all the time. The heart is one hard worker!

You'll know that you've found your pulse when you can feel a small beat under your skin. Each beat is caused by the contraction (squeezing) of your heart.

When you run around a lot, your body needs a lot more oxygen-filled blood. Your heart pumps faster to supply the oxygen-filled blood that your body needs. You may even feel your heart pounding in your chest.

http://kidshealth.org/kid/htbw/heart.html#

MATERIALS

Stopwatch

Heart Rate Chart

Notebook & Pencil

GETTING STARTED

What do you know about visiting the doctor? When you visit the doctor, he usually checks your

heart by listening to it with a stethoscope. A healthy heart makes a lub-dub noise. But did you know there is a way to check your heart from the outside?

This is referred to as your pulse. You can check your pulse by pressing on the skin anywhere that has an artery running beneath it, usually your wrist and neck work the best.

Have you ever wondered why your heart races after you get done running? Well today we are going to find out why and learn how to find our pulse!

PROCEDURE: RESTING HEART RATE You will be learning how to find your pulse and calculate

your heart rates before and after exercise.

Demonstrate how to find your pulse (by pressing with two fingers lightly on your wrist) and direct each student to practice. *See Figure Below.

Count how many times your heart beats in 30 seconds. Ask a volunteer to start the stopwatch and stop it after 30 seconds.

*The heart rate is found by counting the number of heart beats per minute.

Multiplying the number of heartbeats for 30 seconds by 2 to find your heart rate.

PROCEDURE: EXERCISE HEART RATE Run in place for 1 minute while someone times you

with a stopwatch (or other timing device).

Sit down and count the number of times your heart beats in 30 seconds after running.

Multiply this number by 2, just as you did when you found your resting heart rate.

Record both of these numbers in the chart provided on the next page, or copy it onto a piece of paper.

Compare your resting heart rates and your exercise heart rates. Which was faster? How much faster?

Test your heart rate after other activities too, such as skipping or walking! Which activity will give you the highest heart rate?

QUESTIONS

What is a heart rate?

How is heart rate measured?

What is the difference between your resting heart rate and your exercise heart rate?

Why do you think there is a difference between your resting heart rate and your exercise heart rate?

HEART CHART!

Heart Beater

How many heart

beats in 30

seconds?

Resting Heart Rate

How many heart

beats in 30

seconds after

exercise?

Exercising Heart Rate

Running X 2 = _____ X 2 = _____

Skipping X 2 = _____ X 2 = _____

Walking X 2 = _____ X 2 = _____

SUMMARY

We have learned how to find our pulse and determine our heart rate. It is important to remember that your heart is a vital muscle in your body, therefore it is important for you to take care of it by getting proper rest, exercise, and nutrition!

The next time you are exercising or relaxing before bedtime, take a minute to determine what your pulse is, and then find out how fast your heart rate is! Is it a healthy one?

Healthy Resting Heart Rate: 60-100

RESOURCES

For Teachers http://www.americanheart.org/presenter.jhtml?

identifier=3028650 http://kidshealth.org/kid/htbw/heart.html http://www.indianastandards.org/files/sci/

sci_4_2_4.pdf

For Kids http://kidshealth.org/kid/htbw/heart.html http://www.sciencekids.co.nz/gamesactivities/

keephealthy.html