B. Active Living / C. Movement Competence · Active Living and Movement: Fit, Safe and Skilful

Getting Fitter: Heart, Lungs and How Hard I'm Working

B2 A1.6About 35 minutes

Learning goals

I can explain what cardiorespiratory fitness means.
I can name new things my body can do as my heart and lungs get fitter.
I can check how hard I am working using the talk test, my breathing and my heartbeat.
I can compare my heartbeat counts and explain what they tell me.

Words to know

cardiorespiratory fitness
How well your heart, lungs and blood work together to keep you moving for a long time. "Cardio" means heart and "respiratory" means breathing.

heart rate
How fast your heart is beating. You can feel it in your chest, wrist or neck.

pulse
The beat you feel in your wrist or neck each time your heart pumps.

exertion
How hard your body is working.

recover
To get back to normal breathing and heart rate after being active.

capability
Something you are able to do.

Remember from Grade 2

You learned that your lungs take in air with oxygen, and your heart pumps blood with that oxygen to your muscles. You used the talk test and an exertion meter (1 Easy, 2 Working, 3 Hard) to check how hard you were working.

This year you will learn a big word, cardiorespiratory fitness, find out what new things you can do as you get fitter, and learn to count your heartbeat.

A big word: cardiorespiratory fitness

Say it in parts: car-dee-oh-RES-pir-a-tor-ee.

Cardio means heart.
Respiratory means breathing (your lungs).

So cardiorespiratory fitness means how well your heart and lungs work together to keep you moving for a long time.

When you do activities that make you breathe hard often (running games, skipping, biking, swimming, dancing, cross-country skiing), your heart and lungs get fitter.

Cardiorespiratory fitness is about this team: your lungs take in oxygen, your heart pumps it in your blood, and your muscles use it to keep moving.

New things a fitter body can do

As your cardiorespiratory fitness gets better, you may notice new capabilities:

You can keep going longer before you need a rest.
Your rests can be shorter.
You can go a greater distance, like walking or biking farther.
You recover faster: your breathing goes back to normal sooner.
Everyday things feel easier, like climbing stairs or walking up a snowy hill.
You can keep up in long games like tag or soccer.

These changes happen slowly, over weeks of regular activity. Keep at it!

Three ways to check how hard you are working

The talk test. Can you sing? (Easy.) Talk but not sing? (Working.) Only say a few words? (Hard.)
Your breathing. Slow and normal, faster, or huffing and puffing?
Your heartbeat. Put your hand on your chest, or find your pulse. The faster it beats, the harder you are working.

How to find your pulse

Wrist: Turn one hand palm up. Put the first two fingers of your other hand on the thumb side of your wrist. Press gently.
Neck: Put two fingers gently on the side of your neck, beside your windpipe. Press gently, and never on both sides at once.
Use your fingers, not your thumb. Your thumb has its own beat that can mix you up.
Can't find it? Put your hand flat on your chest instead. That works too!

Counting your heartbeat

Ask a grown-up to time 15 seconds while you count each beat. Write down the number. Then you can compare:

After sitting still, the number is low.
After a walk, it goes up a little.
After hard activity, it goes up a lot.

Here are one student's counts:

Heartbeats counted in 15 seconds by one student: 22 after sitting, 27 after walking and 38 after jumping jacks. The harder the activity, the higher the count.

Worked example

Let's read the heartbeat chart

Look at the chart above. Which activity made the student's heart work the hardest? How many more beats were there after jumping jacks than after sitting?

Find the tallest bar: jumping jacks, with 38 beats.
Find the sitting bar: 22 beats.
Subtract to compare: 38 − 22 = 16.
Think: jumping jacks use big muscles in the arms and legs, so the muscles need more oxygen and the heart pumps faster.

Jumping jacks made the heart work hardest, with 16 more beats in 15 seconds than sitting.

Worked example

Let's spot a new capability

In September, Noor could jog around the park path 2 times before she needed to walk. She played tag at recess and biked most days. In November, she jogged around 4 times before walking. What changed?

Compare: 2 times in September, 4 times in November. That is 2 more times.
Why? She was active often for about two months.
Her heart and lungs got fitter: her cardiorespiratory fitness improved.
Her new capability: she can keep going longer and go a greater distance.

Noor's cardiorespiratory fitness improved because she was active regularly. Now she can jog twice as far before resting.

Just for fun

A hummingbird's heart can beat more than 1,000 times a minute when it is flying. That's more than 250 beats in just 15 seconds. Good luck counting that!

Hands-on activity

Heartbeat scientist

You need: a timer (a phone or clock with a second hand), paper, a pencil and a grown-up.

Sit still for 2 minutes. Find your pulse (or put your hand on your chest). Count beats for 15 seconds while your grown-up times. Write it down.
Walk around the room or yard for 1 minute. Count again right away. Write it down.
Do a hard activity for 1 minute: jumping jacks, running on the spot or fast skipping. Count again right away.
Rest for 2 minutes with slow breaths. Count again. Is it coming back down? That is recovering.
Make a bar chart of your 4 numbers. Which was highest? Which was lowest?

Safety: If you feel dizzy, sick or have pain, stop and tell your grown-up. Move in a clear space with no tripping hazards.

Your turn

What two body parts does cardiorespiratory fitness talk about?

Name two new capabilities you might notice as you get fitter.

Name three ways to check how hard you are working.

Where can you find your pulse?

Why should you use your fingers, not your thumb, to find your pulse?

After 1 minute of skipping, will your heartbeat count be higher or lower than after sitting?

Do it and check: Find your pulse at your wrist and count for 15 seconds while a grown-up times.

More practice: warm-up

What does cardio mean?

True or false: you get fitter after just one day of exercise.

At which level of the talk test can you sing?

Name one activity that is great for cardiorespiratory fitness.

What does recover mean?

More practice: on your own

Ben's heartbeat counts for 15 seconds were 24 after sitting and 36 after running. How many more beats after running?

Two weeks ago, Kai needed a 3-minute rest after a long tag game. Now he needs 1 minute. What does this show?

Mia can say a few words at a time but cannot talk in full sentences. How hard is she working?

Why does your heart beat faster when you run?

Is walking slowly to the mailbox a good way to build cardiorespiratory fitness? Explain.

Challenge

Lina counted her heartbeats for 15 seconds: 23 after sitting, 40 right after running, and 29 after 2 minutes of rest. Explain what each number tells her.

Plan a way to test whether your fitness improves over a month. What will you measure, and when?

Jacob says, "My friend's heartbeat count was higher than mine after tag, so he worked harder and I'm lazy." Is that a fair conclusion? Explain.

Check your understanding

Quiz

What does cardiorespiratory fitness mean?

Which is a sign that your cardiorespiratory fitness has improved?

Where can you feel your pulse?

After 1 minute of jumping jacks, your heartbeat count will usually be...

On the talk test, if you can only say a few words at a time, you are working...

Why should you not use your thumb to count your pulse?

Ava's 15-second counts were 22 (sitting) and 34 (after running). How many more beats after running?

For parents and teachers

Big idea: Grade 3 students identify new capabilities and other benefits that come with improved cardiorespiratory fitness (sustaining activity longer, shorter rests, greater distances, faster recovery) and assess their own exertion using simple self-assessment methods (talk test, breathing, heartbeat).

How to help at home:

Help your child find their pulse. It can take a few tries; a hand flat on the chest works as a backup.
Do the heartbeat experiment together and compare your numbers (yours will be different, and that's fine).
Point out progress: "Remember when you needed to stop halfway up this hill? Today you didn't!"

Common difficulties:

Can't find the pulse. Press gently with two fingers; pressing too hard can make it harder to feel. Use the chest instead.
Comparing with others. Heart rates vary from person to person. Encourage comparing with their own earlier numbers.
Expecting fast results. Fitness changes over weeks, not days.

Health note: The numbers here are for learning, not medical checks. If your child often feels dizzy, has chest pain or unusual shortness of breath during activity, or has a heart or breathing condition, talk to your doctor. A child with asthma should follow their asthma plan.

Math link: Comparing heartbeat counts uses Grade 3 subtraction and bar graphs.