- Extremely low
- Low
- Medium
- High
- Extremely high
Dependent variables
-
The vital lung capacity of participant given in decimetres cubed (dm3) and is measured using a Pasco Xplorer GLX and spirometer
Controlled variables
Table 1.0: List of all the variables that will be controlled in this experiment and explanations and method of how the variables will be controlled.
Materials
- Participants who matches the requirements
-
25 × Fitness level survey * Refer to Appendix
- Fully charged Pasco Xplorer GLX
- Pasco Xplorer Spirometer
- 25 × Sterilized Disposable mouth pieces
- 1 × Stopwatch
- 2 × Pen
- Results table to record data
- Pair of gloves
- 2 × Plastic bag
Health and Safety
- Always wear gloves when handling the spirometer, disposable mouth pieces and alcohol
- Experimenter should dress appropriate when carrying out experiment – this includes closed in shoes and hair tied back
- Always use sterilized spirometer during experimenting – when carrying out multiple trials on the same participant, the same spirometer can be reused on the same participant
- Use a new mouth piece for each participant and immediately dispose the mouth piece into a ‘USED’ plastic bag after trials are completed
Method
Table for recording result
Cleaning and preparing equipments
- Wear gloves on
- Using sufficient amount of cotton balls, soak it in alcohol then drain it until it is moderately dry
- Use the cotton balls to thoroughly clean the disposable mouthpieces and places on the spirometer that will be in contact with the participant’s mouth
- Allow around 1 minute for equipments to dry
- After equipments are dry, secure the mouthpiece on the spirometer
- Ensure that there is no damage to the mouthpiece. If the mouthpiece is damaged, dispose it into the ‘DAMAGED’ plastic bag and use a new mouthpiece for the experiment
Participants completing survey and results * Refer to Appendix for survey
- Ensure participant satisfies the requirements of the experiment – age, weight height and current physical conditions
- Briefly explain to participant about the experiment and ask participant to read the ‘Briefing’ section of the survey
- If agreed, ask participant to sign name
- Record data including, name, age, weight and height of the participant, the date, time and location of when and where the experiment is being carried out
- Ask participant to complete the fitness survey
- Calculate participant’s fitness score and determine which fitness level category the participant fits in
Testing the participant
- Sit participant down
- Ensure participant is sitting upright, his back is straight and feet flat on ground
- Explain to participant that they must inhale as deeply as they can outside of the spirometer, then exhale forcefully into the spirometer. As soon as the participant has finished exhaling, they must immediately inhale as deeply as they can, still with the spirometer in their mouth.
- Ask participant to pinch their nose and hold the spirometer on the other hand. The mouthpiece of the spirometer should be positioned directly in front of the participant’s mouth.
- Turn on the Pasco GLX and connect the spirometer.
- Read the value of vital lung capacity on the GLX. On the homepage, select ‘DIGITS’.
- Press the ‘PLAY’ button, wait for the green light and then begin the experiment
- On the Pasco GLX screen, it will show two sets of values, only record the second number which is located on the bottom half of the screen
- When the number on the screen is stable and not changing anymore (the stableness of the number will only be short due to the rapid breathing changes of the participant – inhaling after exhaling and vice versa), record the number that is shown on the screen
- Allow the participant to rest for 2 minutes before carrying another trial. Use a stopwatch to time the rest
- For the same participant, the mouthpiece may be reused for additional trials
- Repeat steps 4 to 11 until three data values have been recorded
- Dispose the mouthpiece into the ‘USED’ plastic bag after completing all three trials
Calculating the participant’s mean vital lung capacity
Using the Pasco GLX and Spirometer [5]
DATA COLLECTION AND PROCESSING
Recording Raw Data
Table 2.0: This table shows the number participants’ number, their score that they received on the fitness level survey out of 32 and their respective fitness level (extremely low / low / medium / high / extremely high); the participants’ age, weight (kg) and height (cm); the date in year 2009, location and time that the experiment was carried out. The table also shows three repeat sets of data of each participant – each set having two values of (a negative and positive value), the positive added to the negative value is the vital lung capacity of the participant (Refer to Background Information). All values of vital lung capacity is given in dm3.
Table 2.1: This table shows observations made on all participants during the experiment. Qualitative observations were recorded of participants as a whole group and not individually. Qualitative data such as breathing actions, breathing noises and breathing length of time was recorded.
Aspect 2
Processing Raw Data
Table 2.2 This table shows the participants categorised into one of the five independent variables of the experiment (extremely low, low, medium, high and extremely high). Each participants average vital lung capacity is calculated using their results from the three trials (refer to Table 2.0). The overall group’s average vital lung capacity is then calculated. All values of vital lung capacity is given in dm3.
Worked calculations:
Calculating Participant 1’s average vital lung capacity of the three repeated trials and the ‘Extremely low’ group’s average vital lung capacity
Data points: 2.21 2.62 2.85 * refer to Table 2.0 – Participant 1
→ M = 2.21 + 2.62 + 2.85
3
= 2.56
Data points: 2.56 2.64 2.83 3.12 2.77 * refer to Table 2.2 – Extremely low
→ M = 2.56 + 2.64 + 2.83 + 3.12 + 2.77
5
= 2.78
Table 2.3: This table shows the standard deviation of the five data values of each fitness level group (extremely low, low, medium, high, and extremely high). The mean of each group’s vital lung capacity (refer to Table 2.2 for data values) is also shown in this table.
Worked calculations:
Calculating the standard deviation of the five data values of ‘Extremely low’ fitness level group
Data points: 2.56 2.64 2.83 3.12 2.77 * refer to Table 2.2 – Extremely low
Mean of data points: 2.78
S2 = [ (2.56–2.78)2 + (2.64–2.78)2 + (2.83–2.78)2 + (3.12–2.78)2 + (2.77–2.78)2 ]
5 – 1
= 0.0484 + 0.0196 + 0.0025 + 0.1156 + 0.0001
5 – 1
S2 = 0.0465
S = √ 0.0465
Standard deviation = 0.216
Table 2.4: This table shows the comparisons of different group’s of fitness level data. Information such as the t-value, standard deviation and the degrees of freedom is calculated using the groups’ sets of data values recorded in Table 2.2. The table also shows if the respective two sets of data are statistically the same (accepting the Null Hypothesis) or if they are statistically different thereby rejecting the Null Hypothesis (H0).
Worked calculations:
Determining if the data of the ‘Low’ fitness level group and the ‘Extremely low’ group accepts of rejects the Null Hypothesis.
The t-test is a data analysis used to compare two sets of data and determine if the two sets of data are significantly and statistically the same of different.
‘P’ denotes Probability and the critical probability for this experiment is 0.05 or the equivalent, 5%.
If P > t-value then the two sets are the same (i.e. accept the null hypothesis)
If P < t-value then the two sets are different (i.e. reject the null hypothesis)
Degree of freedom for the two sets of data = 8 * refer to Table 2.4
T-value = 1.91
Table of critical values for the t-test
2.31 > 1.91
Therefore the data of the ‘Low’ fitness level group and the data of the ‘Extremely low’ fitness level group are statistically the same, hence accepting the null hypothesis.
Worked calculations:
Calculating the t-value of the ‘Low’ group’s data versus the ‘Extremely low’ group’s data
t = 0.29
√ (0.0136242 + 0.0093312)
t = 0.29
0.15151
t-value = 1.91
Aspect 3
Graph 2.0: Graph showing the comparison between the mean Vital Lung Capacity of the five different fitness level groups. Graph also shows the standard deviation for each of the respective independent variable.
CONCLUSION AND EVALUATION
Aspect 1
Conclusion
Figures in Table 2.4 illustrates that between most of the fitness level groups, there were statistical differences between the total vital lung capacities of the male students. The only groups of independent variables that statistically were the same and therefore accepting the Null Hypothesis were the comparisons between the fitness level group ‘Extremely Low’ and ‘Low’ and the comparisons between the groups ‘Low’ and ‘Medium’. This therefore means that the following comparisons of groups rejected the Null Hypothesis and the mean total vital lung capacity of these groups is statistically different:
- Extremely Low versus Medium/High/Extremely High
- Low versus High/Extremely High
- Medium versus High/Extremely High
- High versus Extremely High
Figures presented in Table 2.3 emphasises the scope of differences in values of the five fitness level groups. The mean vital lung capacity for the group ‘Extremely Low’ is 2.78dm3 and for the ‘Low’ group it is 3.07. This means there is only a 0.29 dm3 between the two groups. As a result, when the standard deviation and t-value are calculated and processed, it shows that the mean values of these two groups are statistically the same. This is also the case for the groups ‘Low’ and ‘Medium’ fitness level as between their two mean values, there is only a 0.2dm3 difference. Again, these values emphasises why statistically, these groups are the same and not different.
The Null Hypothesis was concluded as ‘rejected’ or ‘accepted’ for the comparisons between the five independent variables of this experiment from using values of standard deviation and t-test.
When all data was processed, the degrees of freedom was calculated to be 8. The critical value for this experiment was 0.05 or 5%. The probability value of these two numbers (8 and 0.05) was 2.31.
The t-values calculated in this experiment are as follows
-
Ex Low versus Low 1.91 → < 2.31
-
Ex Low versus Medium 2.63 → > 2.31
-
Ex Low versus High 7.02 → > 2.31
-
Ex Low versus Extremely High 25.7 → > 2.31
-
Low versus Medium 1.33 → < 2.31
-
Low versus High 6.16 → > 2.31
-
Low versus Ex High 22.0 → > 2.31
-
Medium versus High 4.93 → > 2.31
-
Medium versus Ex High 13.9 → > 2.31
-
High versus Ex High 2.58 → > 2.31
In Graph 2.0 the mean vital lung capacity differences between the different fitness level groups are clearly presented. The graph illustrates the minor differences in value between the groups ‘Extremely Low’, ‘Low’ and ‘Medium’, and on the other hand the groups of ‘High’ and ‘Extremely High’ have large mean values of vital lung capacity. The biggest difference in values is between groups of ‘Medium and High’. A reason for this is that participants with extremely low, low and medium fitness level are those that do not do regular exercise but participants with high and extremely high fitness level are those who do regular exercise. Therefore the biggest deviation is between medium and high fitness level as it shifting from participants who do not exercise regularly to participants who do exercise on a regular basis. There is an immense different in values between the medium and high group. Referring back to Table 2.3, the difference between the mean vital lung capacity of the ‘Medium’ fitness level group and the ‘High’ group is 1.59dm3.
Graph 2.0 also presents error bars. The error bars shows how much the data is spread out. The bigger the value for error bars the more the data is spread out. From Graph 2.0 it is seen that the ‘High’ fitness level group has the biggest error bar, therefore having the largest spread of data.
Literature value indicates that the average vital lung capacity for adult males is 4.6dm3. [2] The group that is closest to this value is the ‘High’ fitness level group. A reason for this is that participants in this experiment are between the ages of 15 and 16 and are not fully grown adults yet. Therefore where the ‘Medium’ group is meant to be near the literature value, in this experiment it is not due to the age. As people grow, they are able to build onto their fitness level. One is not born with a definite fitness level but one has to build and train their body to become fit.
In Table 2.1, observations of the participants were qualitatively recorded. The observations in Table 2.1 show that participants with a larger vital lung capacity can sustain their breath for a longer period of time. This confirms the idea that participants who are unfit have short breaths and take more breaths in a certain period of time than a fit person. This is because the body of people who regularly exercise are able to proficiently exchange oxygen and carbon dioxide. In addition they can efficiently store, transport and utilise their oxygen, allowing their body to feel at ease and for example, not gasping for air at vigorous stages of exercising. [1]
Although the apparent observations and values were recorded during this experiment and the data illustrates that with higher fitness level, one has a larger vital lung capacity, several significant factors may have affected the data in this experiment. Factors that may have affected the recorded results are:
- Some participants estimated their weight and height and did not know the exact number. As outlined in this report, height affects lung capacity and the taller the person is the larger their lung capacity usually is. Although, some participants did estimate their height and weight, their stature was very alike the other participants – so therefore it could be recognised if their weight and height is alike the other participants, if yes, then they most probably fit with the requirements of this experiment. Consequently there should not be immense outliers of weight and height in this experiment as all participants’ statue was very similar.
- Participants who performed the experiment in the sun and humidity may have struggled to inhale and exhale maximum breaths due to the uncomfortable weather. During the summertime, when this experiment was carried out, it was very humid and hot and this could have tampered the breathing activity of participants who had to take the test outdoors. The weather may have weakened the breathing ability of the participants. However, the weather should not hugely affect results as participants were asked to fully breathe in and out, forcing their bodies to overcome the norm.
- The fitness level survey was the only evidence of participants’ fitness level and participants may have been bias when answering the questions. Some participants may have not answered truthfully therefore being categorised in a different fitness level group. Even thought this may have occurred, for most participants their total vital lung capacity was suitable for what fitness level group they were categorised in.
Even thought, there are factors which may have potentially affected the results, it is still apparent that fitness does affect one’s vital lung capacity. This is illustrated throughout the report where statistically there is a difference between most groups of fitness level. Participants who were fit and did regular exercise were able to take larger breaths and hence exhale much more carbon dioxide then those who did not do any or not much exercise. [1]
Aspect 2 and Aspect 3
Evaluating Procedure and Improving the Investigation
APPENDIX
Briefing
The aim of this practical is to investigate the human lung function and its relation with one’s fitness level.
The results gained from this practical will enable calculations of one’s fitness level and their lung capacity.
Please note:
- If you currently have or had any lung conditions or illnesses that affected your breathing in the last 5 years, please do not participate in this practical
- Major variations in results may occur and this is nothing to be concerned about
- There will be no long-term effects from participating in this practical
- As information gathered from this practical will only purely be used for scientific analysis, please answer survey questions honestly and carry out tests with all effort
Fitness Level Survey
NAME: SIGNATURE:
- If you had to run at a moderate-high speed, how long would you last before stopping?
- Less than 5 minutes
- Between 5 to 10 minutes
- Between 10 to 20 minutes
- More than 30 minutes
- What’s your experience with strength training?
- I’ve never lifted weights
- I’ve lifted weights before, but not in the last year
- I currently lift weights
- I’ve been lifting weights for more than 6 months in the last two years
- How often do you stretch (includes whole arm and whole leg, etc)?
- I never stretch
- I sometimes stretch
- I stretch before and after every workout
- I regularly stretch and do yoga and/or Pilates
- Currently, how often do you exercise in a week (moderate-high cardio workout for at least 20 minutes)?
- I don’t
- Once or twice a week
- 3 to 4 times a week
- More than 4 times a week
- In the last 3 years, have you ever been involved in a competitive sporting activity outside of school? eg; basketball team
- No
- Yes, for less than a year
- Yes, for 1 to 2 years
- Yes, for more than two years and am currently involved
- What is your usual style of exercise?
- I don’t have one
- Slow exercises – eg; walking, yoga
- Hard hitting exercises for a short period of time – eg; sprinting
- Moderate level exercises over a period of time – eg; jogging, running
- In regards to your current style of workouts, what happens after you finish exercising?
- Light breathing and minimal perspiration
- Moderate breathing and some perspiration
- Moderate-heavy breathing and perspiration
- Sustained heavy breathing and constant perspiration
- How often do you warm-up before working out (at least 10 minutes of light-moderate exercises)?
- Never
- Rarely
- Sometimes
- Always
Extremely low 8 – 18
Low 19 – 20
Medium 21 – 22
High 23 – 24
Extremely high 25 – 32