Respiration is the way that the body cells are able to function properly, without it we would die. Respiration involves the breathing, circulation and digestive system, these are three very main systems in the body. The whole idea for respiration is that energy should be produced to be used by cells so that they can function properly. During the process glucose, a sugar produced by the body, reacts with oxygen to release energy which is then used by the cell. Carbon dioxide and water are produced by this reaction and these are waste products.
The equation for aerobic respiration is below:
Glucose + oxygen carbon dioxide + water (+ energy)
This sort of respiration is called aerobic respiration, because oxygen is taken from the air and used. Aerobic fitness (see pilot results) is also linked to this
Respiration is needed because it lets the body break down the food that we eat and release energy from it and the cells need energy to keep the body alive. It is also used as energy to keep the body at the same temperature, warm in winter and cold in summer.
Aerobic respiration provides cells with energy to move. However during exercise, more energy is used and often the blood cannot supply the oxygen needed to the cells in question. When this happens oxygen cannot be used in respiration because there is no oxygen, respiration is carries out without any oxygen and this is known as anaerobic respiration.
The equation for anaerobic respiration is below:
Glucose lactic acid + energy
Even though anaerobic respiration is good, because it can be carried out with a lack of oxygen, it produces a waste product called lactic acid, as the body cannot breath out lactic acid, as it does with CO2 it needs to be broken down. Lactic acid is broken down after exercise by a process needing oxygen. Oxygen is needed to break down lactic acid and the amount needed is known as the oxygen debt. Even thought the body has stopped exercising it needs to recover from the exercise and pay off the oxygen debt.
The equation for oxygen debt repayment is below:
Lactic acid + oxygen carbon dioxide + water
These processes help the body to live and mean it can have a constant supply of energy to keep it living.
Before the start of exercise, the pre-exercise heart rate usually rises
above normal, and this is called an anticipatory response. This is shown in the graph below.
Now I can see that exercise increases the heart rate and oxygen is taken in by the lungs and used in respiration to create energy for the cells.
I need to prove this in my experiment.
HYPOTHESIS: I predict that when a person exercises their heart rate will increase according to the amount of exercise that they do. As stated above, after a while the oxygen debt will occur and their heart rate will stay at as steady level, as it can only be pushed to a certain limit. The oxygen breathed in and the breaths taken will become equal and a steady exercising heart rate will be established. I predict that there will be a 45% increase in the pulse rate for the first 3 or 4 minutes of exercise and then there will be a gradual evening out, until it is at a steady, elevated rate. I predict this because of the graph on page 2. I predict this rate will be above 100 because a resting pulse rate is normally between 50-60 B.P.M. and with exercise in progress, the pulse rate will certainly elevate by 2/3, if not then to have doubled. I predict that when exercise is carried out, the pulse rate will be elevated, maybe even doubled.
VARIABLES: Below are listed the independent, dependent and control variables for my experiment.
INDEPENDENT VARIABLES: This is the variable I will be changing in my experiment to see ‘if exercising for different amounts of time creates a significant difference between the pulse rates of different people.’
The variable, as the title suggests, will be the amount of time taken to exercise. I am choosing this variable because time is an easy thing to measure rather than the control variables, which could have been used as dependent variables instead. For example, if age or pulse rate was my independent variable, it would be harder to measure as the specifications are not exact. With time, however, I can create even steps, 2mins, 4mins, 6mins etc. and get a good set of results and a good graph reading.
DEPENDENT VARIABLES: The dependent variable is the variable I will be measuring in this experiment. The dependent variable is the pulse rate. I will measure this in beats per minute (B.P.M.) I will measure the pulse at the neck, in the carotid artery. I will measure the pulse for 15sec and then multiply it by four to get a more accurate result. This is accurate because it means that if someone has been exercising and then their pulse is taken, it will be slowing down and so it will be different, whereas if it is taken over a smaller period of time it will be nearer the actual pulse rate for a minute.
CONTROL VARIABLES: The variables that I will be keeping the same in my investigation are:
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Sex: I will keep this the same as men and women have different body builds and men are usually bigger than women are. I will need to keep the sex the same to make sure my results are not biased by having different sexes in them, as this would make them inaccurate. The sex I will have in my investigation will be male.
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Age: I will keep the age in my investigation as the body develops at different times in life. For example, if I took a five-year old and a twenty-year old, they would have different fitness capacities and so the results would be different. For this reason I must keep the age the same so the body is developed in the same way. The age I will be using for my investigation will be year 10 (aged between 14 & 15).
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Weight/Mass index: I will keep the weight the same as otherwise a person heavier/lighter may be slower/faster and this would effect my results. As I am a conducting the investigation I will use my own body weight (70 kg) in this investigation. My body mass index :
Mass 70 (Kg.)
Height 2 1.832 (metres) = 20.9 Kgm2
I will make sure that people in my experiment have the same body mass
index (roughly) as me. This will mean that their body build will be roughly the
same and so their fitness level about the same.
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Pulse rate (B.P.M.): I will make sure the people doing my experiment all have roughly the same resting pulse rate as me (64 beats per minute). They will have between 5 on either side.
i.e. between 59 and 69 B.P.M.
This will ensure that all my results are as accurate as can be.
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Type of exercise: I will need to ensure that the type of exercise carried out is the same, as if it was easier for some, and harder for others, it would change the results as different people would be trying at different levels. Thus, the exercise must be the same, but the timing different.
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Time of day: The time of day when this experiment will be taken is very important as this will affect the capacity of the person exercising. I fit is taken after a big meal they will not be able to perform as well as if they had had nothing to eat for a few hours and left time for their food to be digested. Therefore I need to have a set time of day to test this experiment and a limit to eating before it. The time of day will be 15:00 hours and the person will not be able to have eaten ANYTHING for the past 2 hours. This means that every person who takes part in the experiment is the same
SUMMARY OF VARIABLES:
- The things staying the same in my experiment are:
Sex _ MALE
Age 15 YEARS
Weight/Mass index 20.9 Kgm2
Pulse rate (B.P.M.) BETWEEN 59 AND 69 B.P.M.
Type of exercise EXERCISE BIKE, DIFFERENT TIMES
Time of day: TIME OF DAY: 1500
NO FOOD FOR 2HOURS BEFOREHAND.
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The variable changing in my experiment will be:
The amount of time taken to exercise VARIES PER PERSON
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The dependent variable I am measuring to see how healthy a person’s heart is, is:
Pulse Rate VARIES PER PERSON
APPARATUS: The apparatus I will be using for this experiment is:
One person (me) (resting pulse rate of 64)
Stopwatch
Two fingers with which to take pulse rate ‘Turnturi ergometer W2’ (see over sheet)
PILOT METHOD: The method I will carry out to gain my pilot results is laid out below.
For my pilot method and to gain my pilot results, I will use myself to carry out the investigation.
- Firstly I will set up the apparatus, it is as above.
- I will measure my resting pulse rate because I can then see the difference between my pulse rate when exercising and when resting. This is the basis for my experiment and so I will compare the two pulse rates to comprehend how the pulse rate changes. (all pulse rate measurements are taken for 15secs and then multiplied by 4 to create a more accurate result.)
- I will set the pressure on the bike to ‘100’; this is about a third of the hardest level on the bike. I will set the bike timer for 2 mins and start pedalling.
- I will keep over 75rpm (revolutions of the wheel per minute) to know that I have been doing the same difficulty of exercise the whole way thorough the experiment.
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The Exercise: The whole exercise order is:
- Get on bike
- Set timer
- Set ‘pressure of bike’ to 100
- Start pedalling
- Continue pedalling over 75rpm
- Pedal for set time
- Stop pedalling when the time is finished
- Take pulse, (as described below)
- Set up equipment for next time
- Wait until pulse is normal resting rate (see below)
- When the timer is finished, I will sit down upright on a chair and wait for the following time:
Rest for 1 min + then take pulse for 15 secs
Rest for 45 secs + then take pulse for 15 secs
Rest for 45 secs + then take pulse for 15 secs
This means that I will take my pulse for 3 different minutes in total and will have an accurate result of how my pulse rate decreases. From these results I can calculate my aerobic fitness.
- Now that I have my results I will rest for 10 minutes, to make sure my pulse rate has returned to normal and then check my pulse. When my pulse is back to normal, I will repeat the procedure again for 4 then 6 and then 8 minutes as these steps go up in 2 minutes and this seems a good range because it will let me have enough information to change my method for my real results.
FAIR TEST: To make sure my experiment is a fair test I will do the following:
- Keep bike pressure at 100.
- Keep pedalling at over 75rpm.
- Take 3 pulse readings to get an accurate result.
- Keep all the control variables the same (which will be done as it is just me taking part in this experiment).
- ALWAYS rest for 10 minutes between exercising and recording results.
PILOT RESULTS:
Below are my results for the experiment:
‘A table to show how the pulse rate changes during 3 minutes
in the aftermath of varying times of exercising and thus the aerobic fitness’
Aerobic fitness shows how fit the muscles (especially the heart) are. It is designed to be used on an exercised pulse rate (hence the anomalous result for ‘0 minutes exercising’). A high aerobic fitness suggests a well trained and healthy body, above 90 is excellent and above 70 is good
From my pilot results I can see that the more exercise done, the higher the aerobic fitness and pulse rate become. However I think there is a limit to how high they can become and so my actual method and results will change to allow me to collect this data and be able to analyse it properly.
ACTUAL METHOD: Now that I have carried out my pilot method I can see some changes that need to be made to my method for my actual investigation. These changes are highlighted in bold italics.
For my actual method and to gain my real results, I will use 50 different people.
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Firstly I will set up the apparatus, (as it is on the apparatus page.) My apparatus will also include a person to time everybody doing the experiment. This is because they will then have an accurate time and this will mean my results will be more accurate. I will also instruct the timekeeper how to measure a pulse (still in the neck) so that the results will be more accurate. If I asked everybody to take their own pulses there would be mayhem so I will have one person to take the pulse rates and then they will count in the same way, and this will hopefully reduce the amount of anonymous results.
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The pulse measurer will measure the resting pulse rate of all participants because I can then see the difference between my pulse rate when exercising and when resting. This is the basis for my experiment and so I will compare the two pulse rates to comprehend how the pulse rate changes. (all pulse rate measurements are taken for 15secs and then multiplied by 4 to create a more accurate result.)I will set the pressure on the bike, for the participants to ‘100’; this is about a third of the hardest level on the bike. I will set the bike timer for 2 mins and they will start pedalling.
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I will keep over 75rpm (revolutions of the wheel per minute) to know that the participants have been doing the same difficulty of exercise the whole way thorough the experiment.
-
The Exercise: The whole exercise order is:
- 1) Get on bike
- 2) Set timer
- Set ‘pressure of bike’ to 100
- Start pedalling
- Continue pedalling over 75rpm
- Pedal for set time
- Stop pedalling when the time is finished
- Take pulse, (as described below)
- Set up equipment for next time
- Wait until pulse is normal resting rate (see below)
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When the timer is finished, I will sit the participant down upright on a chair and wait for the following time:
Rest for 1 min + then take pulse for 15 secs
Rest for 45 secs + then take pulse for 15 secs
Rest for 45 secs + then take pulse for 15 secs
This means that I will take my pulse for 3 different minutes in total and will have an accurate result of how the participant’s pulse rate decreases. From these results I can calculate their aerobic fitness.
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Now that I have my results I will rest the participant for 10 minutes, to make sure their pulse rate has returned to normal and then check their pulse. When their pulse is back to normal, I will repeat the procedure again for 2/ 4/ 6/ 8/ 10/ 12/ 14/ 16/ 18/ 20 minutes as these steps go up in 2 minutes and this seems a good range because it will let me have enough information to change draw a graph and analyse my results.
- In my experiment, 50 people will take part, all with the same control variables. i.e., someone who:
Sex _ MALE
Age 15 YEARS
Weight/Mass index 20.9 Kgm2
Pulse rate (B.P.M.) BETWEEN 59 AND 69 B.P.M.
Type of exercise EXERCISE BIKE, DIFFERENT TIMES
Time of day: TIME OF DAY: 1500
NO FOOD FOR 2HOURS BEFOREHAND.
Every person will people participate in the exercise regime and will do each different time of exercising (2/ 4/ 6/ 8….) and will start from the bottom, 2 mins and work their way to the top, 20 mins. They will only do 1 exercise a day, at 15:00 hours, to make sure the test is fair. They will each do the exercise 5 times, to get a reliable result, they will do one amount of exercise per week (schooldays) i.e.
WEEK 1) MON - 2mins ex. WEEK 2) MON - 4mins ex.
TUE – 2mins ex. TUE – 4mins ex.
WED – 2mins ex. WED – 4mins ex.
THUR – 2mins ex. THUR – 4mins ex.
FRI – 2mins ex. FRI – 4mins ex.
And so on… This would take 10 weeks to complete.
I will then average the pulse rate so I can use that as my results.
HOW MY RESULTS WILL BE ANALYSED: I will need a recorder to write down all the results in this experiment as well as the pulse measurer. When all my results are written down I will average them in a table and check and point out any anomalous results. I will then plot a graph of my results and take reading from the graph to prove my hypothesis correct. I will achieve this by calculating the % increase of pulse rate and how long it took for this increase to occur. I will then compare these results to the information I have about fitness and pulse rate and see if they are similar and match up. If they do then I will have just clarified that my results are accurate but if they do not match up then I will have to find a reason for it and express ideas as to why the data was not correct. For example;
‘Could it have been the participants, did they not work hard enough?’
‘Was it the pulse measurer?’
‘Was it the type of exercise, did they not work to the same level?’
‘Were the resting pulse rates taken wrongly?’
‘Was the apparatus not functioning correctly?’
These are all questions I will need to ask if my results do not match up with my knowledge of pulse rate.
I will then make a conclusion of my results and evaluate my investigation.
