1. Sonja Silva
HES 403 Lab
VO2 max
4/23/15
Introduction:
VO2 max is the maximum amount of oxygen that your body can use while training at a
maximum workload. It is used as a measure of metabolism and aerobic capacity in athletic
performance. A higher VO2 max is better for optimal performance. The purpose of this lab was
to determine VO2 max in individuals using a treadmill test.
Methods:
1) The subject was required to wear a heart rate monitor during the test.
2) The subject was connected to a breathing tube and headgear on the treadmill. Gas was
calibrated for the treadmill test.
3) The subject warmed up by walking at a comfortable pace for three minutes. Resting heart
rate was recorded.
4) The subject began running at a chosen speed for about eleven minutes or until volitional
fatigue, using a scale to indicate levels of fatigue.
5) Grade was increased by 2% after the first minute, and 1% for every remaining minute
while a machine recorded VO2.
Results:
Our subject’s VO2 max was 61.8 ml/kg/min.
Conclusions:
VO2 max is a good measure of aerobic capacity in trained and untrained individuals. In this test,
we were able to determine VO2 max based on several indicators: an RPE scale, age predicted
heart rate, VO2 levels, and RER. VO2 is influenced by mitochondrial density, muscle fiber
recruitment, and capillary density in the muscle, and therefore we should see a higher VO2 max
in trained individuals (Richards 2012). Increased demand for oxygen and energy to the muscle
that is elicited by training increases the mitochondrial density, the amount and types of muscle
fibers recruited, and the capillary density to increase blood flow to the area. We generally want
the test to last between 8 to 11 minutes. If it is too short, we risk not reaching the true VO2 max.
If it is too long, the subject may be past the point of fatigue and VO2 will start to decrease.
The treadmill test is a good method of measuring VO2 compared to other methods. In the study
“Validating the Arm-Leg Eliptical Ergometer”, it was shown that an elliptical ergometer can be
used to determine VO2 max. However, there was a slight statistical variation in the correlation of
heart rate and VO2 max between males and females. This could be due to higher muscle fiber
recruitment in males due to the inherent difference in upper body strength between genders,
leading to increased VO2 max on the ALE with increased heart rate. A treadmill test may be

2. better to account for this variation, when testing for aerobic capacity between males and females.
ALE ergometer tests could be used for lower impact for special populations due to the fact that
there is no statistical difference in VO2 max for both these tests.
In the treadmill VO2 max test, we used an RPE scale to determine fatigue. Once the subject
reached a fatigue level of 16, we determined that the subject was one minute away from VO2
max. We can see from the graph of VO2 versus time that at the end of our test, VO2 began to
level off. This is a good indicator that the subject reached VO2 max. The heart rate was also very
close to the age predicted maximum of 197. Also, in the last minute of the test, RER should be
close to 1.04. The subject’s RER approached 1.02 at the end of the test. It is likely that we
achieved close to a true VO2 max due to these criteria for a good VO2 max test.
The graphs show that VO2 increased rapidly at the beginning of the test, likely due to the
recruitment of muscle fibers and increased blood flow to tissues. It then began to level off as the
subject reached VO2 max. Heart rate increased linearly as VO2 increased. Ventilation increased
linearly over time, as we would expect from the subject requiring more oxygen with increasing
exercise intensity. Between 8 and 10 minutes on the graph, ventilation increased rapidly. This is
an indicator that the subject has reached a maximal workload, and the body is pausing to take in
more oxygen. (Elsangedy 2013). This is true because the subject reported an RPE value of about
18 at this time. RER increased over time, likely due to increased carbohydrate oxidation with
increased aerobic metabolism. We see an increase of VE/CO2 and VE/O2 over time, with
VE/O2 overlapping at the end. We know that there is increased breathing off of CO2 compared
to inhalation of O2 according to the RER value, so the overlap is due to the ratio of ventilation
over CO2 exhaled, making the constant smaller. (See Appendix for graphs). This test showed
appropriate physiological responses over time, and we were able to obtain a value close to the
VO2 max for our subject.

3. Appendix:
This graph describes the relationship between VO2 and Heart Rate over time.
This graph depicts aerobic threshold in terms of VE/CO2 and VE/O2 over time.
20
25
30
35
40
45
50
55
60
65
155
160
165
170
175
180
185
190
195
200
4 6 8 10 12 14
VO2(ml/kg/min)
HearRate(bpm)
Time
Heart Rate and VO2 vs Time
Heart Rate
VO2
20
22
24
26
28
30
32
34
36
38
40
4 6 8 10 12 14
VE/CO2andVE/O2
Time (min)
VE/CO2 and VE/O2 vs. Time
VE/CO2
VE/O2

4. This graph demonstrates ventilatory breakpoint as Ventilation during exercise over time.
This graph is of RER or the ratio of substrate utilization over time.
0
20
40
60
80
100
120
4 6 8 10 12 14
VE(L/min)
Time (min)
Ventilatory Breakpoint (VE vs.
Time)
0.7
0.75
0.8
0.85
0.9
0.95
1
1.05
4 6 8 10 12 14
RER
Time (min)
RER vs. Time
RER

5. References:
Brown, Andrew. Kueffner, Tannin. O’Mahony, Erin. Lockard, Michael. Validity of Arm-Leg
Elliptical Ergometer for VO2max Analysis. “Journal of Strength and Conditioning
Research.” Lippincott Williams and Wilkins.
Colorado State University. “Maximal Oxygen Consumption.” HES 403 Lab Manual. 2014.
Elsangedy, Hassan Mohamed. The rating of perceived exertion is not different at the ventilatory
threshold in sedentary women with different body mass índices. “Journal of Exercise
Science and Fitness.” Volume 11, Issue 2, Pages 102–106. December 2013.
http://www.sciencedirect.com/science/article/pii/S1728869X13000397#
Klentrou, Panagiota. Ventilatory breakpoints in boys and men. “Human Kinetics Journals.”
Volume 18, Issue 2, p. 216-225. May 2006. http://journals.humankinetics.com/pes-back-
issues/pesvolume18issue2may/ventilatorybreakpointsinboysandmen
Richards, Jennifer. Muscle contraction duration and fibre recruitment influence blood flow and
VO2independent of contractile work during steady-state exercise in humans. PubMed.
NCBI. Exp Physiol. 2012 Jun; 97(6): 750–761.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3366163/