Hi there, I'm Mrs. Kim, and welcome to today's lesson all about the recovery time after exercise.

So let's get started then.

Today's lesson then our outcome will be, I can plot a line graph to display data on pulse rate and use it to determine a person's recovery time after exercise.

These are some of the key terms that you will use today.

And if you would like to pause the video and read them in more detail, please do.

Otherwise, know that I will be going through every single one of those as we move through the slide deck.

We actually have three learning cycles today.

The first one is fitness, drawing a line graph, and interpreting the results.

So we will start with fitness.

What we'd really like to know then is what does it actually mean to be physically fit? Do you think of yourself as a physically fit person? And if so, why do you think that? If not, why do you think that? What's the reason? What does it actually mean? Well, if we put that together, it means that first of all, your bodily systems are all working together efficiently.

So your circulatory system, your digestive system, all of those things that contribute to you being a full organism are working really well.

You're also able to carry out your normal day activities pretty easily.

So if you walk to school, you don't feel really tired, you don't feel out of breath, you are just sort of getting there and it feels normal and easy.

You're also going to be able to engage in other activities such as sport.

So here's a person doing some climbing there, a little bit of bouldering, maybe that's what you like to do.

And actually, a couple of times a week, maybe you really push yourself to do something a little bit more energetic.

Scientists would like to measure fitness then because it gives us a sort of indication of lots of different things.

And some of the measurements that they might take are things like your heart health, your flexibility.

You can see in that picture there, that wonderfully flexible lady doing a bit of yoga.

Endurance, so how long you can keep going with things.

And your BMI.

Remember BMI is your body mass index.

You met that earlier on in the unit.

Now actually, it's really important to remain fit and it can be really helpful for longevity.

So how long you live for, but also how well you are in those later years.

So it may add another 10 years, but those 10 years of really good years of being super duper fit, Imagine an elderly person that actually loses strength in their legs.

What's going to happen to them and how will that contribute to their overall health? Well, they'd no longer be able to go out and exercise.

So if they like to go for a walk or maybe they are part of a club, actually they might not be able to do that anymore.

As a consequence of that then, they're actually not going to be able to leave the house as much and they're not going to be able to make those social connections that they would do normally and that might lead to them feeling sad or lonely and not contributing to a good mental health.

This can contribute then to an overall decline in health.

So both physical and mental.

So it's really important that we set really good healthy ways when we're younger so that we can carry on to continue with those as we get older.

Which of the following are key measurements of fitness? Is it A, BMI; B, heart health; or C, age? I'll give you a moment to think about it, but if you need more time, please do pause the video.

Okay, did you think of two of them? Of course, it's BMI, that body mass index, and your heart health.

Excellent, well done.

So one way that we can measure fitness, remember, is to look at that heart health.

So actually, what we can do is we can track a person's heart rate before and after exercise.

We have done this before in a previous lesson where we've taken our pulse rate, okay? And we can practise taking our pulse right now just to remind ourselves.

So we take our hand, here it is, and our wrist and our thumb side of our wrist we take our other two first fingers and we place those just in this little space here that's on the wrist.

And if we just press very, very gently with those two fingers, we should be able to feel that pulse just there.

It might be that you're wearing a super clever watch that can actually take that value for you.

So we're going to be looking at measuring our pulse rate before and after exercise, okay? And the pulse rate before exercise is known as the resting pulse rate.

The time that it takes for the pulse rate then to return back to that resting pulse rate, this is known as the recovery time and that's going to give us an indication of how fit you are.

Okay, onto our next check.

Use some of the words in the box to complete the sentences please.

The time it takes for the heart to return to the resting, blank, after exercise is called the, blank.

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

Okay, did you have pulse rate for the first one? Fantastic.

And recovery time for the second one.

Well done.

Okay, so when we want to measure our resting pulse rate then, we need to sit still for two minutes, okay? This is going to make sure that we're very calm in our pulse rate and our heart is going at a normal speed.

Place your two fingers from one hand against the wrist of the other hand and feel that pulse.

Start the stopwatch.

Count the number of pulses in 30 seconds.

And then because we want that to be in a minute, we need to times that by two.

We record that in our table and we should repeat that three times because sometimes your pulse rate can go up and down by quite a lot.

And actually, therefore you can pick out any anomalies.

So any results that don't fit that normal pattern and maybe repeat it again.

We can then calculate the mean of the three measurements.

Let's have a go then at turning that pulse rate into beats per minute.

So if Izzy has counted 38 pulses in 30 seconds, what is the pulse rate in beats per minute? Now, because it's only 30 seconds, we've got two 30 seconds in 60 seconds, which is a minute.

So what we need to do is we need to times it by two.

So 38 times by two is equal to 76 beats per minute.

I'd like you to have a little go at this one then.

So Jacob counts 42 pulses in 30 seconds.

What is the pulse rate and beats per minute? I'll give you a moment to think about it, but if you need more time, please do pause the video.

Okay.

Did you know that we needed to multiply it by two? So 42 times by two gives us 84 beats per minute.

Excellent, well done.

So this is how we would collect our data then.

And this is what I would like you to do.

So this is our method.

You can find it on your worksheet.

You can also find a data table so that you can record your results in there.

So if you'd like to get your data, your worksheet out and look for task A for me, I'll give you some time to carry out this method.

But if you need more time, please do pause the video.

Okay, so I've actually got some data for you that yours may look like.

So I calculated the resting heart rate at 60 beats per minute, and then I collected all these pulse rates for eight minutes, okay? And you can see that actually, it's decreasing every time.

Yours may not be exactly the same as this pattern and you may have quite a vary in different numbers and I don't want you to worry about that.

Everybody is different.

So once we've got our data then, what we want to do is we want to put that into a graph.

So our next learning cycle is drawing a line graph.

Now, we usually display data in a graph because it makes trends and patterns easier to see for the scientist.

But when we're plotting a graph, we need to think about what type of graph.

There are actually quite a few different types and we are going to be using either a bar chart or a line graph.

Now remember that a bar chart we use for categoric data, okay? So categoric data is where we have names or labels.

A line graph is where we've got numbers.

So it is continuous data and those numbers will probably be within a range.

The data for recovery time is continuous, okay? We are using numbers the whole time, aren't we? And so therefore we know that we are going to be drawing a line graph.

I would like everybody to get out a ruler, a pencil, and some graph paper.

It's really important that we use a ruler and a pencil for drawing a line graph 'cause we often make mistakes when we're plotting and drawing things and it's just so much easier to be able to rub it out than have to start all over again every time.

So here's my piece of graph paper and I would start by thinking about my x and my y-axis.

Now, this is the x-axis here, the horizontal line along the bottom, and that's going to have my independent variable.

Remember the independent variable is the one that I changed.

The dependent variable then is gonna go on this y-axis you saw just appear on the graph paper there.

And this is going to be my dependent variable as I said.

So the one that I will be measuring.

Here is my graph paper with the axis drawn then.

So some students were asked which variables should be on which axis.

Who do you think is correct? Sam has said the control variable should be on the x-axis and the independent variable on the y-axis.

Jacob, the dependent variable should be on the x-axis and the independent variable on the y.

Izzy, the independent variable should be on the x-axis and the dependent variable on the y-axis.

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

Okay, did you put C, Izzy? Fantastic.

Well done.

Of course, the independent variable needs to go on our x and our dependent variable should be on our y.

Okay, I'm going to demonstrate to you how we would then put that onto our axis.

But there's a couple of things to note.

See how my axis uses up at least half of the page.

You want to make sure that that happens.

And also just as a little note, there's actually only three pieces of data that we're going to plot on here, whereas normally, you would want at least five on a line graph in order to be able to be certain that there's a pattern within there.

But just for this demonstration purpose, I'm just using three.

Okay, so you can see here that we have time after exercise on the x-axis and that's because that is my independent variable.

In brackets, I've put min, which stands for minutes.

That's my units.

On the y-axis, I've got pulse rate.

And again, in brackets, I've got beats per minute.

That is my dependent variable and those are the units for this.

You will notice that every time I've increased my axis, so along the bottom, I've got one, two, three, they go up by the same number of boxes each time.

Okay, so they are evenly spaced increments.

You can see along the bottom there that to get from nought to one, we've got 20 little squares.

From one to two, we've got 20 little squares.

And from two to three, we have 20 little squares.

That's very, very important because each of those little squares needs to equal the same amount each time.

How we can find out how much each of those little squares represents then is if we take the number that is on the axis.

So we're going to do the pulse rate up the side look, which I've gone up 20 squares for a hundred.

Then what I need to do is I need to divide that number, that pulse rate, a hundred by 20, and that tells me that every little square is worth five.

So we can use that when we need to plot.

So at zero time, we need to plot 162, okay? So you can see where my little cross has appeared.

All right, it's going to be, I need to find first of all where 150 is and then I go up another two and a bit tiny squares and I put my cross in there.

We can then plot one, which is going to a hundred.

That's an easy one look because it's already on that line.

So that's a super one to find and I'll put my little cross in there.

And then finally, 95.

So in order to get to 95, I can work out how many fives go into 95, which is 19.

Okay, and so I know that I need to go up 19 squares.

And there it is.

So I put my little cross in there.

Now you can either join these points up, point to point, but you must use a ruler.

You mustn't use a wiggly line.

Or you can put in something called a line of best fit.

And actually, this makes quite a nice smooth curve.

So for this one, I might put in a smooth curve.

If you don't get a smooth curve, please do join them up point to point with a ruler.

I would then add a line for the resting pulse rate as a dashed line along the bottom.

And you can see that we haven't quite made it to the resting pulse rate yet, but I'm sure that if we continued with this practical taking the data, then they would get down to that resting pulse rate.

So put it in on your graph as a little dash line.

So let's have a little check that we know which type of graph that we're using.

So which type of graph should we use for continuous data? A, a bar chart; B, a pie chart; or C, a line graph.

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

Excellent.

Do you get C, a line graph? Well done.

So we all know which type of graph that we need to use today.

So onto our next task of the day, and this is in order to draw a line graph of your results.

If you didn't get collect any results, don't panic, you can use that sample data.

You will need graph paper, a pencil, and a ruler, and potentially a rubber of course as well.

And I'd like you to put time after exercise on that x-axis and pulse rate on that y-axis.

I will give you some time to do that.

But if you need more time, please do pause the video.

Okay, so here are some things that you should have included on your line graph.

So if you want to get your line graph out now, we can check the parts together.

So the independent variable is on the x-axis and you have labelled it with units.

So for example, time after exercise in minutes.

Give that a tick if you got that right.

The dependent variable on the y-axis is labelled with units, okay? For example, pulse rate or beats per minute.

Tick that.

Have you remembered to do your increments on that x and y-axis evenly so they have the same number of little boxes between each one? If you have, give yourself a tick.

Have you correctly plotted your data? Now, if there is anyone that you could work with on this, it's really good to check somebody else's plotting.

It's quite hard to check to check your own plotting, okay? 'Cause you may just make the same mistake again.

Have you either put in a nice smooth curve as a line of best fit or maybe your data was a bit more up and down.

So you might have actually put in a straight line, but you must have used a ruler.

Then have you remembered to put your resting pulse rate along the graph in a dashed horizontal line? So I'm gonna show you what my graph looks like with that sample data.

If you did the sample data, you might want to pause it now so that you could quickly check it through.

But you can see that I've done all of those different points there.

I've made sure that I've labelled my axis, my increments are evenly spaced, and I got my points joined up with a ruler.

Although actually, I could have put in a smooth line of best fit for this one as well.

I've also put my resting pulse rate as a dashed line.

Now, actually, my resting pulse rate was 60, so the heart rate actually returned to normal after six minutes.

So that person is probably pretty fit.

Okay, so we could say that they got down to their resting heart rate in six minutes after exercise.

So we would say that their fitness levels are good.

Okay, then I'm sure you did really well with that.

We're now onto our final learning cycle of today, interpreting the results.

So recovery time, of course, is how fast your heartbeat returns to that resting rate and it's after stress.

Okay, so exercise is included in that where you've put a stress on the body.

Exercise, of course, is really good for maintaining a healthy heart and also a good cardiovascular system.

All right, so your heart and then all of those blood vessels that are involved in that, moving that blood around your body.

Exercise builds and strengthens your heart muscle.

Remember the heart muscle is made of cardiac muscle and just like any other muscle that you have, so your biceps, the more you work it out, the bigger and stronger they will get.

And the stronger that your heart muscle is, the shorter your recovery time will be.

If your heart does not recover well, it could be a sign of poor fitness.

And remember that could affect your overall health.

We spoke about that earlier, didn't we? In learning cycle one.

This graph then shows the data for the heart rate of recovery time in two different people.

They both had the same resting heart rate.

We've got person A that is in blue and person B that is in that sort of purple colour.

Person B then, we can see actually has a much steeper decline in their heart rate.

So it returns to normal, that resting heart rate, in a much shorter time period.

And that would be their recovery time as they got straight down into there.

So after about five minutes.

This indicates that they have a higher level of fitness than person A, who actually even after the eight minutes, have not returned to their resting heart rate.

That's a really good indication then that one person is fitter than the other.

Okay, true or false, the longer it takes for a person's heart rate to return to their resting rate, the fitter they are.

Is that true or is that false? Can you justify your answer? A, person who is fit would have a shorter recovery time.

B, a person who is fit would have a longer recovery time.

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

Okay, so did you realise that that was false? Of course it would be 'cause that person would actually have a shorter recovery time if they were fitter and not longer.

Excellent, well done.

All right, onto our final task of today then is task C.

Number one, what effect does exercise have on a person's heart rate? What happened? Number two, what happens to a person's heart rate after they stop exercising? Number three, imagine you compare the resting heart rate of two people, one who exercises regularly and one who does not get any exercise.

Who would have the shortest recovery time and why? I'll give you a moment to answer these, but if you need more time, please pause the video.

Please record your answers on your worksheet.

Okay, let's mark those off then.

So number one, heart rate increases.

Number two, heart rate gradually returns to its resting rate.

Number three, the person who exercises regularly will have a shorter recovery time.

This is because their heart muscle will be strong and they will have good cardiovascular health.

Excellent, really well done.

If you'd like to add a few more bits to your answer, please do do that now.

Otherwise, we're actually onto the very last part together then.

We are onto the summary.

So let's have a think about what we have actually learned during this lesson.

When someone is fit, it means their body systems are working properly and they can carry out physical activity easily.

We can investigate how fit someone is by measuring their pulse rate in beats per minute before and after exercise.

Exercise helps to build muscle, including the heart.

Recovery time is how long it takes for a person's heart rate to return to its resting rate after exercise.

This can be determined from a line graph.

A fit person will have a shorter recovery time.

I hope you've enjoyed today's lesson and I hope that you have learned something new there about fitness and about recovery time, and hopefully I will see you again soon.

Thanks for listening with me today.

Bye.