The gender of the participants.
Apparatus
Consent form^{}
Spirometer (cubic centimeter, /cm3)
Stopwatch (seconds
10 disposable mouthpieces
Spinning bike
10 participants were chosen to take part in the experiment (age 1819).
Method
 Hand out consent form and ask participant to sign.
 Put mouthpiece into hose opening of the spirometer.
 Make sure the indicator of the spirometer is set on 0 by adjusting the indicator.

Inhale normally. Put mouthpiece in mouth and exhale normally. . Repeat 3 more times. Measure volume and record as tidal volume.

Inhale as deeply as possible. Put mouthpiece in mouth and exhale as much air as possible. Repeat 2 more times. Measure volume and record as vital capacity.
 Bike on the spinning bike for 5 min.

Inhale normally. Put mouthpiece in mouth as fast as possible and exhale normally. Measure volume and record as tidal volume after exercise.

Quickly after inhale as deeply as possible. Put mouthpiece in mouth and exhale as much as possible. Measure volume and record as vital capacity after exercise.
Data Collection and Processing
Table 1. Measurements of tidal volume and vital capacity before exercise (*Processed data).
By calculating the standard deviation of the tidal volume and vital capacity before exercise it is possible to see to what extent the values deviate from the mean value. It is calculated by using the following equation:
Standard deviation =
Standard deviation of the mean tidal volume before exercise:
=
= 571.44 100
Standard deviation of the mean vital capacity before exercise:
=
= 929.36 100
Table 2. The mean and the standard deviation of tidal volume and vital capacity before exercise.
Table 3. Measurements of tidal volume and vital capacity after exercise.
The standard deviation of the tidal volume and vital capacity after exercise are as follows: Standard deviation of tidal volume after exercise:
=
= 790.28 100
Standard deviation of vital capacity after exercise:
=
=1310.64 100
Table 4. The mean and the standard deviation of tidal volume and vital capacity after exercise.
By using bar graphs it is possible to compare the values of table 1 and table 3 to see the effect of shortterm exercise on tidal volume and vital capacity of the lungs.
Graph 1. Mean tidal volume for each participant before exercise / tidal volume after exercise (100) incl. standard deviation.
Graph 2. Mean tidal volume for all participants before exercise / mean tidal volume after exercise (100) incl. standard deviation.
Graph 3. Mean vital capacity for each participant before exercise / vital capacity after exercise (100) incl. standard deviation.
Graph 4. Mean vital capacity for all participants before exercise / mean vital capacity after exercise (100) incl. standard deviation.
Student’s ttest
To determine whether the differences in the data found from before and after exercise are due to random fluctuation, a paired ttest must be conducted.
Tidal volume:
Null hypothesis: The tidal volume of the lungs will not increase after shortterm exercise (5min).
Alternative hypothesis: The tidal volume will increase after shortterm exercise (5min).
Table 5. Values relevant to the ttest: The mean tidal volume and standard deviation of tidal volume before and after exercise.
Table 6. Values relevant to the ttest: mean difference in tidal volume, tvalue and degree(s) of freedom.
Vital capacity:
Null hypothesis: The vital capacity of the lungs will not increase after shortterm exercise (5min).
Alternative hypothesis: The vital capacity will increase after shortterm exercise (5min).
Table 7. Values relevant to the ttest: The mean vital capacity and standard deviation of vital capacity before and after exercise.
Table 8. Values relevant to the ttest: mean difference in vital capacity, tvalue and degree(s) of freedom.
Table 9. Critical values of the tdistribution calculated according to the probability of an alpha value and degrees of freedom.
As the tvalue for tidal volume is 4.5479 and the α value is 1.7341, making the tvalue higher than the α value, the alternative hypothesis for tidal volume is accepted.
As the tvalue of the vital capacity is 0.7252 and the α value is 1.7341, making the tvalue lower than the α value, the null hypothesis for vital capacity is accepted.
Conclusion and Evaluation
By looking at tables 1 and 3, and graphs 1 and 3, it is possible to determine the effect of shortterm exercise on the tidal volume and vital capacity before and after exercise.
It can be seen from the results in tables 2 and 4 and graph 2 that the mean tidal volume increases significantly after 5 minutes of exercising on a spinning bike from 1352cm3 to 2270cm3. The standard deviation of the tidal volume is 569.78 before exercise and 790.28 after exercise, which demonstrates the spread of data, however, the participants used were males and females who have significantly different tidal volumes and it is therefore difficult to generalize it. The ttest, on the other hand, shows the significance of the change in tidal volume. The tvalue of the tidal volume is 4.5479 (4.5479, as the negative sign is ignored), which is greater than the critical value (α) of 1.7341 and the alternative hypothesis was therefore accepted, which supports the original hypothesis that the tidal volume of the lungs increase after shortterm exercise.
When looking at the results for the change in the mean vital capacity in table 2 and 4 and graph 4 it is difficult to conclude whether the values increase or decrease or don’t change at all because the mean shows a distorted view of distribution of values. The standard deviation of vital capacity before exercise is 932.87 and after exercise 1310.64, which means the data deviate far from the mean but it must be taken into consideration that the participants were males and females and they inhibit very different vital capacities. The ttest shows that there is no significant difference in the vital capacity before and after exercise as the tvalue was 0.7242 and the critical value (α) was 1.7341, which is higher than tvalue and thus, the null hypothesis was accepted – the vital capacity of the lungs does not increase after shortterm exercise.
Hence, it can be concluded that the results obtained do, to some extent, support the theory as the tidal volume did increase but the vital capacity did not.
However, limitations of this investigation to consider include: the speed at which the participants were biking, height and weight, gender differences, the method of using the spirometer, number of participants and repetition.
The speed at which the participants were biking was uncontrolled and some rode very fast whereas others didn’t. This can have affected the range of the results but it wouldn’t have had any implications on the final conclusion. However, to avoid this inaccuracy the spinning bike should be installed at a fixed speed.
The weight and height of the participants can also have a huge effect on tidal volume and vital capacity. This was an uncontrolled variable, which may have affected the results crucially, which could have been improved by measuring the weight and height of the participants and taken those measurements into consideration.
Since this investigation made use of male and female participants the ranges of values in tidal volume and vital capacity are very high. Males have shown to have higher tidal volume and vital capacity than women. This uncontrolled variable did not affect the results negatively as the final results were as expected. However, it qualifies as a limitation and it could have been improved by separating participants by gender.
Another weakness of this experiment is the misunderstandings of how to blow into the spirometer accurately. Participants were unsure of the method. This could have had a negative effect on the results and could have been improved by giving the participants a more detailed explanation, with illustrations, of how to use the spirometer properly.
The number of participants in this was also very sparse, which was not enough to infer accurate results. This could have been improved by gathering more participants, of both genders, to take part in the experiment.
Lastly, the number of trials done on the tidal volume and vital capacity was too low as 3 are not enough to provide accurate results. To improve this variable the number of trials could have been increased to 10 trials, which would give a more accurate mean of the tidal volume and vital capacity before and after exercise.
Nevertheless, this investigation succeeded in demonstrating the effect of shortterm exercise on the tidal volume and vital capacity of the lungs, which was the initial aim.
Appendices
Appendix I
Consent Form.
· I have been informed about the nature of the experiment
· I understand that I have the right to withdraw from the experiment at any time, and that any information/data about me will remain confidential
· My anonymity will be protected as my name will not be identifiable.
· The experiment will be conducted so that I will not be demeaned in any way.
· I will be debriefed at the end, and have the opportunity to find out the results.
I give my informed consent to participating in this experiment
NAME and date____________________________________________
Contact number_____________________________________________