Mallori Kolar
Bio 142 Lab Report
Jenny Lee
Effects of Physical Activity on the Human Body
INTRODUCTION
Exercising benefits the human body in many ways including weight control,
fighting health conditions and diseases, and an overall boost of energy and mood.
During physical exercise your body must compensate for the many variations that
will occur. The compensations usually involve your body temperature rising as your
muscles heat up and the regulation of breathing and heart rate to fix levels of oxygen
consumption and carbon dioxide concentration. During exercise, your carbon
dioxide levels increase causing you to breathe harder and faster to eliminate any
excess carbon dioxide. Also during exercise, your heart rate increases triggering
your body to send more oxygen to the muscles to remove carbon dioxide faster.
This experiment is important to all fields of research. This experiment
observed various stages through out exercise to distinguish changes in heart rate,
carbon dioxide clearance, oxygen consumption, skin temperature, hemoglobin
saturation, and mean arterial pressure. It is important because society claims that
people need to stay healthy to avoid health risk but they need to be able to
individually know what their body is doing and it’s limits.
In this experiment, it is hypothesized that during exercise, each of the values
for the following elements (heart rate, carbon dioxide clearance, oxygen
consumption, temperature, hemoglobin saturation, and mean arterial pressure) will
increase during exercise and gradually decrease during the resting period down the
original values.
METHOD
The experiment was conducted on one male and one female subject who
exercised by running at given speeds and inclines from the information in Waters’
Exercise Physiology Lab Manual. Prior to exercise we calculated an exercise heart
rate so the subjects wouldn’t over exert themselves during exercise and stay safe.
For the respiration phase, a spirometer collected the tidal volume, a capnometer for
carbon dioxide clearance, and an oxygen analyzer for oxygen consumption. To
calculate carbon dioxide clearance, the number given by the capnometer is divided
by 760 mmHg to get the percent carbon dioxide of exhaled air, then it was
multiplied by tidal volume and respiratory rate to get liters per minute. To find
oxygen consumption, you subtract the value given by the oxygen analyzer from
20.9%, and then multiplied by tidal volume and respiratory rate. A
sphygmomanometer as well as a heart rate monitor was used to calculate blood
pressure and then used to compute mean arterial pressure (= 2/3 x diastolic +1/3
systolic). An observation key was given to determine the physical state that
occurred during exercise. Also a skin thermometer found body temperature and a
pulse oximeter found hemoglobin saturation.
The resting phase occurred before the physical activity. The subjects were
sitting down while information was taken at zero and three minutes. There is no
control subject in this experiment because everybody’s bodies are different. We
used the resting points for each subject as a baseline for the experiment. During the
exercise portion that typically lasted for 15-18 minutes depending on when subjects
reached their maximum exercise heart rate. The data points occurred while the
subjects were continuously running, the collection of data typically lasted about a
minute. The subjects were running on the treadmill with data points occurring
every three minutes with the incline on the treadmill with each data point, the speed
was not increased until minute fifteen. The recovery data points were collected after
the subject either reached their maximum heart rate or ran for 21 minutes. The
recovery lasted six minutes and consisted of walking for the first three and sitting
for the next three while data was taken. Throughout the entire experiment data was
taken every 3 minutes from the heart rate monitor, capometer, oxygen analyzer,
spirometer, and observation list. The remaining tools were only used during resting
and recovery periods.
RESULTS
Fig. 1: Changes in Heart Rate
Heart Rate (Bpm)
Changes in Heart Rate
200
180
160
140
120
100
80
60
40
20
0
Subject !
Subject 2
0
3
3
6
9 12 15 18 3
6
Resting--Physical Activity--Recovery (min)
Figure 1 shows the pattern of heart rate from the resting period to the recovery. In subject 1 you can
see that heart rate increased with physical activity and then dropped during recovery. During the
experiment, we were unable to collect the heart rate at every 3-minute interval as shown above. If we
were able to collect information, I believe it would follow the same pattern as subject 1.
Fig. 2: Changes in Carbon Dioxide Clearance
CO2 Clearance (L CO2/ min)
Changes in Carbon Dioxide
Clearance
6
5
4
3
Subject 1
2
Subject 2
1
0
0
3
3
6
9 12 15 18
3
6
Resting--Physical Activity--Recovery (min)
Figure 2 shows that each subject’s CO2 clearance rose as exercise increased, each subject
peaking towards the end of exercise. The CO2 clearance decreased during recovery to
return back to resting numbers.
Fig. 3: Changes in Oxygen Consumption
Oxygen Consumption (L O2/min)
Changes in Oxygen Consumption
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
Subject 1
Subject 2
0
3
3
6
9 12 15 18 3
6
Resting--Physical Activity--Recovery (min)
Figure 3 shows that oxygen consumption was lowest during the resting period then
continued to increase up until physical activity ceased. After physical activity ceased the
oxygen consumed dropped and then drastically increase in the next three minutes.
Fig. 4: Temperature
Skin Temperature
Skin Temperature (C)
38
37
36
35
34
Subject 1
33
Subject 2
32
31
0
3
18
3
6
Resting-- After Physical Activity--Recovery (min)
Figure 4 shows that the skin temperature increased with exercise. After exercise the skin
temperature gradually decreased but never reaching resting heart rate.
Fig. 5: Hemoglobin Saturation
Hemoglobin Saturation (%)
Hemoglobin Saturation
100
99
98
97
96
Subject 1
95
Subject 2
94
93
0
3
18
3
6
Resting-- After Physical Activity--Recovery (min )
Figure 5 illustrates that during physical activity the hemoglobin saturation decreased. But
during the recovery period it starts to increase again but never reaches the resting rate.
Fig. 6: Mean Arterial Pressure
Mean Arterial Pressure (mmHg)
Mean Arterial Pressure
120
100
80
60
Subject 1
40
Subject 2
20
0
0
3
18
3
6
Resting-- After Physical Activity--Recovery (min )
Figure 6 represents the Mean Arterial Pressure. In the graph, for subject 1 the MAP stays
constant from resting to recovery. While subject 2, the MAP drops drastically after physical
activity and then increases back up towards the resting rates.
DISSCUSSION
Overall, the results found do support the hypothesis that all levels would
increase during the exercise phase. Though, the support must be considered weak
because of the slight variations found for each subject in each graph. For example, in
Figure 5, both participants you see a slight increase at the beginning of exercise but
then it drastically decreases for both. Also during evaluation of the mean arterial
pressure you see that subject 2 stays constant from resting through recovery, where
as subject 1 you see a dip in the graph, which could be a miscalculation or error.
Also in Figure 1, the graph for changes in heart rate, you see subject 2 has a
lot of missing data from the analysis. This missing data causes the graph to not show
a specific trend in the information received. To avoid an error of this kind, the
experiment should be performed again making sure the heart rate monitor and the
heart rate collector are each working together to process the right information.
The variations described may seem to disprove the hypothesis; there are
only slight glitches and a majority of the results coincide with the hypothesis. To
minimize error in this experiment, more data from the individual subject should be
collected so when comparing the results of one subject to another you can make
stronger conclusions.
The experiment overall went extremely well. The participants were very
cooperative with all instructions. However, errors may occur as shown in the above
results. To avoid as many errors as possible, it is important for all conductors of the
experiment stay on task and remains focused until it is complete.
REFERENCES
1. WATERS. "Exercise Physiology Lab." ANGEL. N.p., n.d. Web. 26 Nov. 2012.
<https://cms.psu.edu/section/default.asp?id=MRG-120522-114224-JRW8>.
2. WATERS. "Guidelines for Formal Report." ANGEL. N.p., n.d. Web. 26 Nov. 2012.
<https://cms.psu.edu/section/default.asp?id=MRG-120522-114224-JRW8>.