Hi there, I'm Mrs. Kemp and welcome to today's lesson all about the effect of exercise on breathing and heart rate.

This fits into the diet and exercise unit and you will probably recognise some of the information when you learned about healthy diets back in primary school and also from the skeleton and muscles topic back in year seven.

So let's get started then.

Our outcome for today is I can plan and carry out an investigation into the effects of exercise on breathing or heart rate.

These are some of the key terms that we're going to be using today and please do pause the video if you would like to read those through more carefully.

But don't worry, I will be going through each one as we make our way through the lesson.

Today we have three learning cycles, investigating breathing and heart rate, collecting data, and data analysis.

We're going to be starting with the first one then, investigating breathing and heart rate.

So what actually is your breathing rate and your heart rate? Well, breathing rate is the number of breaths you take per minute.

If you put your hand on your chest or your abdomen, you can feel it rise and fall every time you take a breath.

Your heart rate is the number of times your heart beats in a minute.

Often we use pulse rate for that and we'll be going through what that is and how we can take it.

It's usually recorded in BPM, which stands for beats per minute.

So what do you think happens to your breathing rate and your heart rate when you exercise? I bet you've already got some ideas about this.

Have a little think.

So your breathing rate will increase.

Okay? And that's because you need to exchange more gases, okay? You need to get more oxygen in and you need to get more carbon dioxide out.

Remember that those gases move by that process called diffusion.

Diffusion is the movement of particles from where they're in a high concentration, so where there's lots of them, to a low concentration, where there's less of them.

Our heart rate will also need to increase, okay? Because there is that increased demand for oxygen and glucose for respiration.

Then actually the heart needs to pump more blood to those muscles where they're going to be using that oxygen and glucose.

As a byproduct of respiration then, a waste product, carbon dioxide will be produced and therefore we need to try to remove that as quickly as possible from those cells, and that will all be moving via the blood, and that's why heart rate will need to increase.

Because we're going to be carrying out an investigation into this first learning cycle.

Actually, we need to think about what the different variables are for an investigation.

Okay? So these are factors that can be varied or measured in a science experiment.

We've got the independent variable.

This is the factor that is being changed, the dependent variable, the factor that is being measured, and of course, the control variable, a factor that needs to be kept the same to make the investigation valid.

Okay? So these are really important that we can apply these to any investigation that we carry out in science.

Alright, let's do one together then and then I'd like you to do one after.

So together we're going to do the investigating the effect of exercise on breathing rate.

Alright, so the independent variable for this one, the thing that we're going to be changing is the level of activity.

So how much exercise they're going to do and how vigorously.

Dependent variable is the number of breaths per minute.

So you would need to be counting that during the practical and a control variable, something that we'll need to keep the same, the person and also the length of time spent exercising.

Alright, could you have a go at this one on your own then? So you are going to be doing the investigating the effect of exercise on heart rate and you need to think of the independent variable, the dependent variable, and the control variable.

I will give you a moment to think about it, but if you need more time, please do pause the video.

Okay.

Did you think of the independent variable is the level of activity? So actually it was the same as the other one a moment ago.

However, this is the thing that's going to change then, that dependent variable.

Instead of looking at breathing rate, we're looking at the number of heart beats per minute.

If you put your pulse, that is also valid, so that's excellent.

The thing that we're going to keep the same then, the person again, and also the length of time spent exercising.

So let's try to keep those different variables in mind as we continue with this practical.

So our independent variable is the amount of exercise.

The exercise that we're going to be doing is jumping jacks.

You can see a little image of a person there demonstrating a jumping jack for you.

When we are at rest, we're just going to be sitting still for one minute 'cause we will need to take our resting heart rate first.

If you are doing some moderate exercise, then we do 20 jumping jacks in one minute.

Vigorous exercise, so a little bit faster.

We're going to be doing 30 jumping jacks in a minute.

You could use something called a metronome.

So you may have used those in music lessons before and what they do is that they help to keep time, and you can set them to be 20 beats per minute, 30 beats per minute, and then what you do is you do your jumping jack at that moment when it beeps, if you don't have one standalone one as is in that picture, you can actually get these on the internet and set them as you wish.

Okay, so breathing rate or pulse rate will be our dependent variable and to measure breathing rate, all we have to do is put our hands on our chest or just breathe in and out, and count the number of breaths in.

Okay? During 30 seconds.

And then what we do is we multiply it by two so that we can get it into being 60 seconds.

It's much easier to count over 30 seconds and we are much less likely to make mistakes in our counting if we're counting for a shorter period of time.

So that's why we do that and then multiply it by two.

Measuring your pulse rate can be a little bit more tricky.

And there is a little video to go with this, so I'm going to play it in a moment, but essentially what we're going to do is take our hand, okay, your left-hand is the best, take your right two fingers, your first two fingers, and place them into this spot here.

But we'll watch the video for a little bit further instruction.

Okay, so when we then need to record our results, then we will need to be drawing a table.

Remember that when we draw a table, we always write into the title any units that we need and we must make sure that we use a pencil and a ruler, so it's really nice and neat on our work.

That independent variable should be in the left-hand column and then subsequent columns should be made up of your dependent variable.

When we're drawing our table for breathing rate then, this is what it would look like.

I would put in the left-hand column there, my independent variable that is the amount of exercise, we've got resting, moderate, and vigorous.

My dependent variable would be my number of breaths in a minute, so I would need to count that.

Remember over 30 seconds, multiply by two.

I'm taking three readings for each, okay? So I would repeat the activity and then I would take my reading again and then I can calculate a mean, which I will put in that final column.

So there's our independent variable, our dependent variable, three repeats, and then what we're doing is we're adding up those results and we're dividing by the number of repeats.

So we've got three repeats, so I would add up my three repeats, divide by three.

This is going to make my results much more reliable.

Okay? Remember that term reliable.

That's what I would like you to use when we're talking about why we calculate a mean.

Okay, onto our next check of the day then, could you put these following steps in order for taking a resting pulse rate, A, use the first two fingers from one hand.

B, count the number of pulses in 30 seconds.

C, press gently against the wrist of the other hand to find the pulse.

And d, multiply the answer by two to find beats per minute.

I will give you a moment to think about it, but if you do need more time, please do pause the video.

Okay, the first one, use the first two fingers from one hand, press gently against the wrist of the other hand to find the pulse.

Count the number of pulses in 30 seconds, multiply the answer by two to find beats per minute.

Excellent, really well done there.

Onto our first task of today then.

This is task A.

Please do get your worksheets out so that you can record your answers.

I would like you to draw a table to record the results for the investigation, into the effective exercise on pulse rate.

So we've already drawn one, haven't we, for breathing rate? So actually it's going to be very, very similar so you have that in mind when we are setting up our table, we also want to make sure that we are using a pencil and a ruler.

I'll give you some time to think about it, but if you do need more time to draw your table, please do pause the video.

Okay, let's have a look what we've got then.

So in our left-hand column again, we've got the amount of exercise, we've got resting, moderate, and vigorous.

We've got pulse rate this time, in beats per minute in the centre and again, I've left space that I can take three readings.

On the end, I've got a column for mean pulse rate, and that again will be beats per minute.

If you need more time to make some corrections on yours, please do pause the video.

So onto our second learning cycle of today.

This one is titled Collecting Data.

So we actually don't need a great deal of equipment for this.

You might want to have that metronome available.

So you can look online to get one if you need it, but you could just use a stopwatch and just jump when you needed to.

You will also need a stopwatch, some way of timing your activity, and then when you are taking your breathing rate or pulse rate.

This is our method for breathing rate then.

So if this is the one that you're doing, this is the method that you need.

To find your resting breathing rate, sit still for one minute.

Count the number of times your chest rises and falls in 30 seconds.

Multiply the number by two and record in your data table.

Repeat this another two times, repeat steps two to four after moderate and vigorous exercise.

We went through what moderate and vigorous were earlier on.

So if you need to go back and check those, please do.

If you're going to be doing pulse rate then, we need to find your resting pulse rate.

So sit still for one minute, find your pulse by placing your first two fingers of one hand on the thumb side of the wrist of the other.

Count the number of pulses or heart beats in 30 seconds.

Multiply that number by two and record in your data table.

Repeat this another two times.

Repeat steps two to four after moderate and vigorous exercise.

So let's just make sure that once we have collected our data, we are able to calculate a mean.

So I'm gonna go through that first with you and then you can have a try afterwards.

Calculate the mean for the three resting pulse rate measurements of 65, 67 and 66 beats per minute.

You need to add all three measurements together.

So let's do that now.

It gives us 198 and then we divide by the number of measurements that we took.

So we took three measurements, therefore, it's 198 divided by three, which is equal to 66.

Okay, I'd like you to have a go on your own this time.

I will give you a little bit of time to think about it, but if you need more time, please do pause the video.

Okay, so did you add all the three measurements together and get 225? We then divide back that by the number of measurements, which in this case again is three, and therefore, we get 75 beats per minute.

I hope you got the same, otherwise, you maybe need to go back through your calculation and just check where you made a mistake.

Well done.

Onto our second task of today then, and this one is going to be about you collecting some data.

All right.

So what I would like you to do is carry out the investigation.

You can choose either pulse rate or breathing rate, record this in your table and then make sure for number two, I'd like you to calculate a mean value for each amount of exercise, round your values to whole numbers.

There is some sample data if you need it.

If you are not able to calculate your mean.

I will give you some time to think about it but if you need more time, please do pause the video.

Okay, this is the sample data that I provided for you, but obviously, you should hopefully have your own set of data.

So your numbers may look very different to this, and that's perfectly normal, and perfectly fine.

So when we add up our resting pulse rates and divide by three, then we get 56.

When we add up our moderate exercise and divide by three, we get 70.

And then for our vigorous exercise we can see that we add them together, divide by three and we get a 100.

Remember I did ask you to round these up to whole numbers.

Onto our final learning cycle of today.

This one is data analysis.

So we are going to look at that data that we have collected and see what patterns we can find.

Now usually, scientists will display their data in a graph, okay? It makes it much more easier to see a correlation or that pattern that we would like to find.

We should consider when we are going to draw a graph, a bar chart or a line graph in this case.

So a bar chart would be used when the independent variable is categoric, a line graph is used when the data is continuous.

We can see that the bar chart has got bars, the line graph has a line, okay? So it's an easy way of distinguishing between the two, but maybe we're not quite sure about what category continuous data is at the moment.

So what is the difference between that? Have a little think for a moment.

Do you know that yourself? Okay, so in categoric data, the groups are always names or labels.

Here's a couple of examples for you.

We've got eye colour, so they would be things like blue, green, brown, okay? They are names of colours and not numbers.

We could also have types of metals, so you could have gold or silver, okay? And obviously, they are also not numbers.

They are in fact the names of the types of metals.

In continuous data then, it's a number that can take any value within a range and we might have things like temperature when we record temperature, it can obviously increase or decrease across that scale, the volume of gas, all right, is also going to be an example of continuous data.

So there we've got different numbers, haven't we? In an investigation then, the independent variable is changing the amount of exercise.

Which type of data do you think this is? Is it a, categoric, is it b, continuous? I'll let you have a think about that for a moment, but if you need more time, please pause the video.

Excellent, it's categoric, isn't it? Because we've changed the amount of exercise and we had resting, moderate, and vigorous, and of course, they are names, okay, or labels.

They are not numbers, and, so therefore, we need to use a particular type of graph.

Which of those graphs do you think we would use for categoric data? Are we going to use a bar chart or are we going to use a line graph? I'll give you a moment to think about it, but if you need more time, please pause the video.

Did you choose a bar chart? Excellent, really well done.

So how do we actually draw a bar chart? You're going to need a ruler, a pencil, and a piece of graph paper for this next challenge.

Here's my graph paper then.

So we're going to draw the independent variable on the x-axis.

That's the one, the horizontal line.

We're then going to put our dependent variable on that y-axis, and we can see the y-axis appearing there on my graph paper.

Remember, we're using a pencil and a ruler.

In an investigation then, a person's breathing rate is measured at different amounts of exercise.

Which data should we plot on the x-axis? Is it breathing rate, amount of exercise or pulse rate? I'll give you a moment to think about it, but please do pause the video if you need more time.

Okay, did you choose the amount of exercise? Okay, that is our independent variable and therefore, should be on that x-axis.

Excellent, well done.

Here is some sample data then for looking at pulse rate after exercise.

Our resting exercise gave us a pulse rate off 59, moderate was 68, vigorous was 88.

You can see on the screen there then that we've drawn a bar chart.

Let's just have a look at this so that we can learn how to plot that bar chart.

We've got our independent variable on the x-axis.

We've got amount of exercise.

Then we've got the dependent variable, mean pulse rate.

Notice that we have also put beats per minute there.

It's important that we have any units in that title as well.

On our y-axis there.

Then actually what we've made sure that we've done is we've gone above the highest value.

The highest value is for vigorous exercise at 88.

So we've gone all the way up to a hundred.

Make sure that your y-axis also does the same.

Because this is a bar chart and not something called a histogram, then we've got a gap between the bars, that allows us to tell that it is a bar chart.

Please make sure that yours has a gap.

I've also made sure that each bar is the same width because it is representing the same amount of increments and increases, so it must have the same width.

If we wanted to describe bar graph then once we've drawn it, then what we could see here is that actually each bar is getting higher and higher and higher, isn't it? So as the amount of exercise increases, so does the mean pulse rate.

Okay, so that would be a description of what is happening to my graph.

We can then use science in order to explain the reason that the pulse rate is increasing and so we would want to say that the heart rate or you may have put pulse rate, that's fine, increases during exercise to provide more oxygen and glucose to those muscles.

The muscle cells use this fuel for cellular respiration to provide energy to contract.

The blood also removes carbon dioxide from the muscles as it is a waste product of respiration.

So you can see there that there is a distinction between describing, so saying the shape of something, and then explaining using the science to say why we saw that difference or that pattern or correlation.

So let's go onto our check then.

This one is a fill in the gaps.

Okay, I will read it out first.

So heart rate, blank, during exercise to provide more oxygen and glucose to the muscles for, blank.

The muscles use the fuel to provide, blank, to contract.

The blood also removes, blank, blank, it's a double word there from the muscles as it is a waste product of respiration.

I will give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you think of increases, respiration, energy, and carbon dioxide? Brilliant, well done.

So onto our final task of today.

This one is task C.

You can record your answers on your worksheet.

You will need to get your graph paper ready as well, and a pencil, and a ruler because I would like you to draw a graph of your results or the sample data if you didn't manage to get any results.

Describe the shape of your graph and explain the shape of your graph.

Remember, describe saying the shape, explain using the science to say why that correlation occurred.

I'll give you some time to think about it, but if you need more time, please do pause the video.

Okay, so you should have drawn a bar chart.

First of all, let's make sure that we've got our independent variable on the x-axis.

Okay, so the exercise and then the dependent variables are either our breathing rate or pulse rate on that y.

Make sure that your bars are not touching each other and they are the same width.

If you can check your plotting or even better, if there's someone else with you, ask them to check your plotting for you for each of those bars.

I then ask you to describe the shape of your graph, and that is as the amount of exercise increases so does the mean pulse rate or breathing rate.

Sometimes this doesn't always happen when we're in a laboratory situation, so if you've got slightly different results, it may just have been a miscount or potentially that actually your pulse rate was just a bit funny that day.

Explain the shape of your graph then.

The heart rate or breathing rate increases during exercise to provide more oxygen and glucose to the muscles for cellular respiration.

This provides energy for muscle contraction.

An increase in heart rate and breathing rate also removes carbon dioxide from the muscles and body as it is a waste product of cellular respiration.

If you need to add a little bit into your answer, please do that now and pause the video.

Otherwise, excellent, well done.

You've done really well today.

So we are onto the final summary for today, okay, and I'm gonna go through some of those main points that we learned about in the lesson.

So when investigating the effects of exercise on breathing rate and heart rate, the control variables are the person and the length of time spent exercising.

The amount of exercise is the independent variable.

It is categoric data and goes on the x-axis of a bar chart.

The heart rate or breathing rate is the dependent variable, which goes on the y-axis of a bar chart.

You've done excellent today, you've had a lot to do and we've been very, very busy, haven't we.

Thank you so much for learning with me and goodbye.