Lesson 5 ♥ The Heart Is a Muscle
Objectives
Students will:
U calculate their target heart rate*
U identify the relationship between target heart rate and physical activity*
*Learning Objective
Estimated Class Time
Part A
Calculations and Counting Pulse:
20 minutes
Total Time: 20 minutes
Part B
Monitoring and Graphing Heart Rate:
16 minutes
Conclusion: 4 minutes
Total Time: 20 minutes
Materials Needed
U Teacher 411: Physical Activity (for teacher’s use only)
U Stopwatch, or a watch or clock with a second hand
U Calculating Target Heart Rate worksheet (one copy per student)
U Exercise and Heart Rate worksheet (one copy per student)
U Heart Rate Graph worksheet (one copy per student)
Lesson Preparation
U Review this lesson, including the documents listed in the Materials Needed
section and the Teacher 411: Physical Activity, found at the end of this lesson.
U Make copies of the worksheets in the Materials Needed section.
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The Heart Is a Muscle
Part A
Calculations and Counting Pulse
1. Inform students that in this lesson they’re going to learn about how physical activity affects their
heart rate. Tell them they’ll start by getting an idea of their heart’s pumping action from opening and
closing their hand in a similar motion.
Tell students that when you say Go they should count how many times they can open and close their
hand, squeezing tightly each time, for 30 seconds. Instruct them to open and close their hand
completely each time. Give the signal and then time students for 30 seconds.
Ask a few students how many times they “pumped” their hand. Have them multiply their answer by
2 to get the number of times they would have “pumped” their hand in 1 minute.
Ask how many students pumped their hand between 60 and 100 times. Explain that a number
between 60 and 100 is how many times their heart has pumped—and will pump—every minute of
their life.
2. State or paraphrase the following:
Between 60 and 100 beats per minute is the resting heart rate of most people, including people
your age. But when you exercise, your heart rate increases. Your target heart rate is the range
that should be maintained during physical activity for 20 minutes in order
to achieve the maximum benefit for your heart. The heart is a muscle and,
just like any muscle, the more your heart is exercised, the better it will
work.
Moderate-to-vigorous physical activity, called MVPA, will help you achieve
your target heart rate. What are some examples of MVPA? (Possible answers:
Brisk walking, jogging, running, bicycling, tennis, dancing, jumping rope,
rollerblading)
In this lesson you’re going to calculate your target heart rate and find out how fit your heart
muscle is.
3. Give each student a Calculating Target Heart Rate worksheet. Explain the target heart rate zone
formula and demonstrate its application by going over the example. Then have students complete the
problems. Go over the correct answers. (1. 92–128 bpm; 2. 84–118 bpm; 3. answers will vary) Tell
students to keep this worksheet because they will use it in the next CATCH lesson.
4. Inform students that in the next class they’ll see how quickly their heart rate returns to its normal, or
resting, rate after doing a few minutes of exercise. Tell them that since the activity will require
counting their pulse, you’re going to teach them how to do that now. State or paraphrase the
following instructions:
• To find your pulse, place the index and middle fingers of one hand on the inside wrist of
the other hand. Don’t use your thumb because it has its own pulse, which may interfere
with feeling your wrist pulse.
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The Heart Is a Muscle
• Slide your two fingers toward the thumb side of your wrist.
• Count the number of beats you feel in 15 seconds. Multiply that number by 4. The total you
get is your heartbeats per minute, which is your pulse and your heart rate.
5. Tell students that now they’ll be ready to monitor their heart rate in the next CATCH lesson.
Part B
Monitoring and Graphing Heart Rate
1. Inform students that they’re going to monitor their heart rate to see how quickly it returns to its
normal, or resting, rate after doing exercise. Tell them they’ll also find out why this is important.
2. Give each student an Exercise and Heart Rate worksheet. Briefly go over the directions. Have them
complete Question 1.
3. Lead students in finding their resting heart rate, using the instructions in Part A of this lesson. Time
them for 15 seconds as they count their pulse. Then have them multiply the number of beats they
counted by 4 and fill out the third and fourth columns of the chart in the worksheet.
4. Lead students in a physical activity for 2 minutes. You can facilitate this by using your own method
(make sure you demonstrate moderate-to-vigorous physical activity), or you can use one of the
suggestions provided below:
OPTIONAL: You may want to do a practice run of the physical activity for 15 seconds to make
sure that everyone can do the activity and can hear you when you ask them to stop.
• Perform the following activities inside or outside the classroom, alternating between the different
exercises: running in place, jumping jacks, knee lifts, squats, jumping rope with an invisible rope,
push-ups, and free style.
• Students could be taken to an outdoor area to run around for 2 minutes, as long as they are all
active and can be quickly gathered to an area where they can easily hear you.
5. After the 2 minutes of physical activity is up, have students wait 15 seconds. Then instruct them to
(1) count their pulse when you say Go and (2) record the number of beats they counted in the
“Immediately after exercising” row under “Beats counted in 15 sec.” (Remind them not to perform
the multiplication at this time.)
6. Students should continue this pattern of waiting for 15 seconds, counting their pulse, and recording
the number of beats, until that number is the same as it was for their resting heart rate, or until the
second column is filled—whichever comes first.
7. Instruct students to (1) do the calculations needed to complete the third and fourth columns of the
chart, (2) complete the Heart Rate Graph worksheet, and (3) answer Questions 1–3 below the graph.
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The Heart Is a Muscle
Conclusion
1. As time permits, ask a few students to share their answers to Questions 1–3.
2. State or paraphrase the following:
During exercise, a healthy heart quickly soars to within its target range. The better shape a
heart is in, the faster the heart rate will return to normal—that is, its resting heart rate.
Also, people who exercise regularly often have a very low resting heart rate. This is because
their heart is stronger and pumps more blood each time it contracts.
Finally, the heart is a muscle, and muscles need to be exercised to stay strong. Exercising keeps
your heart strong and healthy so that it can continually pump blood through your body. To
have a healthy heart, it’s important to do 60 minutes of some kind of physical activity every
day that puts your heart into its target range for at least 20 minutes.
Extension Activity
• Coordinate with the PE teacher to assign students to take their heart rate while participating in PE
class. Students should take their heart rate at the beginning, in the middle, and at the end of the class.
Have students report their findings in the classroom and graph the results on a Heart Rate Graph
handout.
Sources
• Adapted from HEADS UP 2008 Nutrition/Physical Activity Second Edition module “Target Heart
Rate” and “The Heart is a Muscle” activities
• Physical Activity for Everyone. Centers for Disease Control and Prevention web site:
http://www.cdc.gov/nccdphp/dnpa/physical/everyone/recommendations/index.htm
• Physical Activity for Children: A Statement of Guidelines for Children Ages 5 - 12, 2nd Edition.
National Association for Sport and Physical Education web site: http://www.aahperd.org
Additional resources can be found in the appendix.
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