Lesson video

Hi everyone, my name is, Miss Hummel and together we'll be answering the question, what effect does exercise have on the muscles? In this lesson, we will learn about muscles and how they work.

We will also learn what happens to our muscles when we exercise and how people strengthen and grow their muscles.

Our lesson will follow this structure.

First, we will recap our previous knowledge of this unit, then we will learn about muscles followed by muscle pairs.

Finally, we will learn about exercise and the muscles.

In this lesson, you will need an exercise book or paper, a pencil or pen, a coloured pencil or pen, and a ruler.

If you haven't got those things, pause the video now and go get them.

Here are our star words, which are the most important words of our lesson.

I'm going to say them and ask you to repeat them after me.

When I point at myself, it will be my turn, and when I point at you, it will be your turn.

exercise, muscles, muscle pairs, contract, relax, fibres, tightness, carbohydrates, proteins.

Well done.

We will begin by recapping our knowledge of a balanced diet and how this can be affected by lifestyle.

First, you should complete this task where you should write what you need to have a balanced diet.

There were seven essential nutrients.

What were they all? Pause the video and resume once you've finished, get ready to mark your work.

You should have said carbohydrates, fibre, protein, fat, water, minerals, and vitamins.

Well done to those of you that got all seven.

Next, you should match the nutrient to its role in your diet.

On the left hand side, we have the nutrients which are protein, fibre, carbohydrates, and fat.

On the right hand side, we have their roles in our diet, which are, release energy when broken down, growth and repair, stores energy, keeps you warm and protects your organs, keeps food moving through your gut.

Pause the video to complete this task and you can resume once you finish.

Get ready to mark your work.

So protein should have matched with growth and repair, fibre matched with keeps food moving through the gut.

Carbohydrates should have matched with release energy when broken down and finally fat matches with stores energy, keeps you warm and protects your organs.

Your next question is what is a balanced diet? Pause the video to answer the question, and you can resume once you've finished.

Get ready to mark your work.

A balanced diet means eating the right types of food in the right amounts so that the body gets the nutrients that it needs.

Next, we've got an activity that says who would need the most energy, on here, and why? Who do you think would need the least amount of energy, and why? You can pause the video to complete the activity and you can resume once you've finished.

Finally, you should answer this question.

What is nutritional deficiency? Pause the video and resume when you've finished.

You should have said, "Nutritional deficiency refers to when you do not have enough of one or more nutrients in your diet." Now let's learn about our muscles and how they work.

The human body contains more than 650 muscles.

That is a lot of muscles.

Now here's the basic information that we need to know when a muscle contracts, it gets shorter, and when a muscle relaxes, it gets longer.

When one muscle relaxes the other one contracts.

So let's dive a bit deeper and get a little bit more information than that.

I would like you to listen closely, and take notes about anything that you think is going to be important to remember.

So first we said already that the human body contains more than 650 muscles.

Those muscles are attached to our bones.

When a muscle contracts, it shortens and pulls on a bone making us move, muscles always work in pairs.

While one muscle is contracting, the other one is relaxing.

And when muscles contract, they become shorter and fatter.

And when the muscles relax, they become longer and thinner.

The pairs of muscles are called antagonistic muscle pairs.

Let's say that again.

So the pairs of muscles are called antagonistic muscle pairs, and they're the pairs where, when one contracts, the other one relaxes.

Now it's time for you to answer these questions.

How many muscles are there in the body? What must a muscle do to pull on a bone? When one muscle in a pair of contracts, what does the other do? Pause the video to answer those questions, and you can resume when you've finished.

Get ready to mark your work.

So the human body contains more than 650 muscles.

To pull on a bone a muscle must contract.

When one muscle is contracting, the other muscle is relaxing.

Now answer these two questions.

First, describe the appearance of contracted muscles, and then we've got, describe the appearance of relaxed muscles.

Pause the video, to answer the questions and resume when you've finished.

Get ready to mark your work.

So contracted muscles are shorter and fatter, and relaxed muscles are longer and thinner.

Let's see if we can maybe come up with an action to help us with that.

So contracted muscles are shorter and fatter, and then we've got relaxed muscles, which are longer and thinner.

Let's discuss what we mean by muscle pairs.

Try and see if you can remember the word of what we call the muscle pairs.

Now, pairs of muscles were called antagonistic pairs.

Your turn.

Antagonistic muscle pairs, well done.

Remember that when one muscle relaxes, the other one is contracting.

In the diagram, which muscle is relaxing and which one is contracting on the top picture? Now, point to the muscle that's relaxing.

Now, point to the one that's contracting.

How did you know which one was contracting and relaxing? You should have said that you knew because the shorter muscle and fatter muscle is the one that's going to be contracting, the longer and thinner muscle is the one that's going to be relaxing.

And then what about the diagram at the bottom? So point to the one that's relaxing.

Point to the one that's contracting.

Okay, notice how they are opposites in that particular exercise.

So now let's have a look really at what's happening in our body.

And let's see if maybe you can have a go at maybe examining what's happening in some different stretches and flexes.

So in the diagram on the right, we can see the person flexing their bicep.

What they're doing is that they're getting their arm, oh, you're going to struggle to see on this camera, and they are pulling it towards them.

It's not just pulling it towards them though.

They're trying to flex it.

So they're trying to almost press as hard on their hand as they can, and really feel that muscle.

And when they're doing that, they're feeling the muscle here, the bicep get bigger.

Now you try it.

So have it relaxing, and now do that and see if you can feel that muscle getting bigger, so therefore it's shorter, and it's fatter, which is why you can feel it.

And then, so that's our bicep muscle that you're feeling.

So what's happening to our tricep, which is behind it, which is its antagonistic muscle pair? So the other muscle is going to be relaxing when you're flexing that bicep muscle.

And then what happens if you use the tricep muscle and not the bicep muscle? So say you've got your arm outstretched and then you're moving it towards the middle of your body this time.

Okay, so now you can feel where your tricep is, which is kind of here behind your arm, and I can definitely feel that get bigger and smaller as I move it like that.

Therefore, our bicep is also changing, it's relaxing while our tricep is contracting.

So now let's see if you can try both of those so that you can hopefully experience because when we experienced it ourselves, we're more likely to remember in the future.

Hopefully now that you've experienced it yourself, it should be easier to label the diagrams to explain what's happening to each muscle during the movement.

So pause your video now to complete this task and then resume when you finish.

If you think you're going to be stuck with this task, stick around for a few sentence stems that might help you.

Now, if you're here because you need a little bit of help.

So when we fold our arm up our bicep mmm, and our tricep mmm, so when we were doing this one, our bicep mmm, and our tricep is mmm, and when we move our arm inwards like this, our tricep was mmm, and our bicep was mmm.

So try and use that to help you.

Now, get ready to mark your work.

So when we fold our arms up like this, our bicep is contracting and our tricep is relaxing.

And when we move our arm inwards towards our body, our tricep contracts and our bicep relaxes in this case, hopefully you were able to get that right.

Finally, we're going to learn how exercise affects our muscles.

Have a think first, what do you think happens to our muscles during exercise? Think about these people running, for example, what's happening to their muscles? When we use our muscles to move, the fibres that make up our muscles need to contract and relax.

So you can seek what the fibres would have looked like from a muscle in this diagram here.

So those fibres are either contracting, which means they're getting shorter and fatter.

So like that, or they're relaxing.

So if you've ever had play dough for example, and you've had the same amount of play dough, you could make it kind of shorter and fatter, or you could extend it and make it thinner and longer.

The same thing is the case for our muscles.

When we use our muscles a lot, or use them to create a large force, for example if we're lifting something, that's a heavy weight, then the fibres in that muscle tear a little bit, that means they break a little bit.

You can see kind of in the image, how maybe few of the muscle fibres are being torn.

So what happens to the fibres in our muscles when they're used a lot, or they need to create a large force? Pause the video to answer the question, and resume when you've finished.

Get ready to mark your work.

So when we use our muscles a lot or use them to create a large force, for example, by lifting a heavy weight, the fibres in the muscles tear a little bit.

Now this is why muscles can be sore when we have exercised them a lot.

The body's working hard to repair the small tears in the muscle fibres.

Now, have you ever been sore after some exercise or a long walk or a hike? I know I certainly have.

Now when the muscle is repaired, it gets a bit stronger and a bit tighter.

So the tightness of that muscle is known as muscle tone.

Sports people will often do a lot of exercise to make their muscles as strong as they can.

Which phrase do you think means the tightness of muscles? It was muscle tone.

With a lot of particular types of exercise, muscles can continue to get stronger and stronger and be made to get bigger as well, so this is what bodybuilders do.

They're people that spend a lot of time doing exercise to make their muscles as big as possible.

Then, carbohydrates are needed to give you the energy to move and for the body to repair.

This means that they're particularly great to fuel our body before exercise, because remember that carbohydrates can be broken up into starch and sugar, and our body's really going to need that sugar during our exercise.

Proteins provide the material that is needed to rebuild the tears in the muscle fibres.

This means that it's great to have lots of protein to repair our body after exercise.

Now answer these questions.

What happens to muscle fibres when they're used a lot? And which phrase means tightness of muscles? And which food group is needed to provide the material to repair muscles? Pause the video, resume when you've finished.

Now, have a different colour pen or pencil ready to mark your work.

So when muscle fibres are used a lot, they tear a little.

The phrase muscle tone means tightness of muscles.

Proteins are required to repair muscles.

Now, based on what we have said, what do you think athletes do to create those stronger muscles? They spend a lot of time doing exercise to make their muscles as big as possible and to make sure their muscles are used to that exercise.

So they're creating that muscle tone.

Finally, I will leave you this question, for muscles to contract they need a lot of energy.

Energy comes from the food that we eat.

How does it get from when we're eating it to our muscles? And that's a good question.

We have now finished our lesson and it is time for you to complete your exit quiz.

You need to exit the video and complete the quiz to test your knowledge and understanding of this lesson.

I hope you enjoyed the lesson, bye.