PEMES 3153 Physiology of Exercise
Lab 7 – Cardiovascular Response To Exercise
As energy requirements increase, so does the demand on the cardiovascular system. Cardiac
Output is an indicator of heart function during exertion. Cardiac output is the total volume of blood
pumped by the ventricle per minute, or simply the product of heart rate and stroke volume. Thus,
heart rate response is an indicator of exercise intensity during aerobic exercise.
The use of heart rate monitors using telemetry has improved our ability to measure heart rate
(or pulse) during exercise. The purpose of this lab experience is to observe the changes in heart rate
with progressive cycle ergometry and then use this data to determine relationships of heart rate to
other physiologic variables.
Measurements
1.
Sit quietly on the bicycle for 3 minutes and record a resting HR and . Next, ride the ergometer
starting at .5 kp and progressively increasing the workload 0.5 kp every minute. Maintain a
pedaling rate of 70 rpm. Use the Polar Heart rate monitors to determine the average heart rate
during the last 10 seconds of each stage. Record the heart rate at each work stage. Discontinue
exercising when you cannot maintain at least 60 rpm. Make sure you record the highest
heart rate attained.
2.
After completing the sequence, record your data in Excel.
Kp/RPM
Power Output
(kgm.min-1)
Resting
0
0.5/70
210
1.0/70
420
1.5/70
630
2.0/70
840
2.5/70
1050
3.0/70
1260
3.5/70
1470
4.0/70
1680
4.5/70
1890
5.0/70
2100
5.5/70
2310
6.0/70
2520
HR (bpm)
Analyses
1. Use Excel to graph the relationship between heart rate and power output for all males and all
females in the class separately. You can do this by averaging the heart rates at each power
output for the males and the same for the females and then graphing these average heart
rates. Graph the male and the female heart rate on the same set of axes with heart rate on the
vertical axis and power on the horizontal axis. On the same graph, add your individual
values for HR at each power output. Label each axis appropriately including the units of
measure and put an appropriate title on the graph.
2. On a second graph, plot the percentage of maximal heart rate versus power output for all
males and for all females. To do this, you will need to compute the percentage of the
maximal heart rate that each heart rate is at each power output (see example below).
Example: HR at power output of 210: 110 Max HR: 195
% of max: 110/195 = .56  56% of max HR
Then, graph the percentage of maximal heart rate versus power just like in #1 above. On the
same axes, graph your individual values for percentage of maximal heart at each power
output. Label each axis appropriately including units of measure and put an appropriate title
on the graph.
Save your data from this lab because you will need it in the next
lab.
Answer the following based on the data.
1. Describe the response of heart rate and percentage of maximal heart rate to power output and
note any differences between the male and female responses.
2. Typically you expect the average male HR to be lower than the average female HR at the
same power output. Is this the case with your data? Why will the male’s heart rates
typically be lower at the same power output?
3. Compare your individual responses to the appropriate gender’s responses. What can you say
regarding your “fitness level” compared to the average of the same gender? Explain.
4. Typically you would expect the true maximal heart rates to be nearly the same for the males
and females in this class. Was this the case? Why are the maximal heart rates expected to
be same for the males and females in this class?