Download Lab 7: BLOOD PRESSURE AT REST AND DURING EXERCISE

SUNY Cortland
Exercise Physiology Lab: EXS 397 Lab
Lab 7: BLOOD PRESSURE AT REST AND DURING
EXERCISE
Name: Ashleigh Genito
Lab Section/Time:4:10pm-6:00pm
I. INTRODUCTION
The purpose of today's laboratory is to familiarize the student with the techniques and
concepts associated with arterial blood pressure. During an exercise bout systolic blood
pressure will increase for one of two reasons. The first reason is an increase in heart rate
(more heart beats per minute) and stroke volume (more blood being pumped per beat).
Because more blood is being pumped through the arteries at a faster rate, more pressure is
being exerted on the arterial walls. The more intense the cardiovascular activity, the
greater the heart rate and stroke volume, and the higher the blood pressure.
The second reason for an increase in systolic blood pressure is a forceful muscular
contraction which compresses nearby arteries, resulting in greater resistance to blood
flow. The more forceful the contraction, the more the arteries will be compressed and the
greater the resistance to blood flow will be, resulting in a higher blood pressure.
Activities like performing squats with a heavy weight increase blood pressure for
both of the aforementioned reasons. They cause large increases in heart rate and stroke
volume because they require the use of large amounts of muscle mass. They also require
very forceful muscular contractions resulting in the compression of arteries, which
surround the muscles. When both of these factors occur at the same time the result is a
very large increase in blood pressure. It is not uncommon for pressures to reach as high
as 300 over 200 mmHg during maximal squats or leg press and even as high as 200 over
80 for runners.
There are four basic pressures which are classified under the general term
"blood pressure." These four pressures and their definitions are as
follows:
1. Systolic pressure: This is the highest pressure observed in the artery and is a
product of the heart's systole (contraction). It is representative of the total heart
energy.
2. Diastolic pressure: This is the lowest pressure observed in the artery and it
results from the drop in arterial tension during diastole (rest) of the heart. It
represents the sum of factors acting contrary to the cardiac force, e.g. peripheral
resistance.
3. Pulse pressure: This is the difference between the systolic and diastolic
pressures. It represents the efficiency of the heart indicating the extent to which it
overcomes the peripheral resistance. Pulse Pressure = Systolic-Diastolic
4. Mean pressure: This is the average pressure to which the arteries are subjected.
Due to the irregular shape of the blood pressure pulsitile curve, it is not the
simple arithmetic mean of the systolic and diastolic pressures, but is more
approximated by the following: Mean Arterial Pressure (MAP)= diastolic
pressure + 1/3 (pulse pressure)
II. PROCEDURES



Please work in groups to perfect your technique for measuring blood
pressure. Switch partners as often as possible. Get a lot of practice on
different people.
Table 1: For a member of your group, record blood pressures (systolic and
diastolic) and heart rate. Be sure to have the subject rest and wait 2
minutes in each position before taking pressure and HR readings
Table 2: Choose one member to perform all conditions. Record their
gender. Then record blood pressure and heart rate for each of the 6
conditions. Finally, calculate Pulse Pressure and Mean Arterial Pressure
for each condition and record in your table.
1. Obtain resting (supine) HR and BP (3 min)
2. Obtain HR and BP dynamic large muscle mass exercise (3 min)
*Standing Squats
3. Supine (3 min)
4. HR and BP during dynamic small muscle mass exercise (3 min)
*Arm Circles
5. Supine (3 min)
6. HR and BP during isometric exercise (1 min) *Hand grip for 1 min
III. RESULTS
TABLE 1. – Effects of body position on BP and HR. Stay still in each position for 2
minutes before taking measurements
Body Position:
Laying
Sitting
Standing
Systolic (mmHg)
102
107
110
Diastolic (mmHg)
60
56
70
HR (bpm)
66
68
72
TABLE 2. – Rest 3 min before moving on to the next exercise
Condition
Rest
(supine)
Small
Muscle
Large
Muscle
Isometric
Exercise
Rest
(supine)
Systolic
(mmHg)
114
Diastolic
(mmHg)
56
63
Pulse
Pressure
58
122
78
75
44
124
81
82
130
76
63
54
93.14
118
60
60
58
79.14
HR (bpm)
43
MAP
75.14
92.54
95.19
IV. DISCUSSION QUESTIONS
1) What effect does body position have on blood pressure and what are the two
reasons for this change?
Muscle contraction standing up = more blood flow
Head is higher so the heart and vessels need to work harder to get the blood to
the brain. Laying down allows for easier and faster flow so the heart doesn’t
have to work as hard.
2) Which of the three exercises created the greatest change in pressure? Which
on heart rate?
Squats had the greatest change in pressure because there are more and larger
muscles working during this exercise. Squats also had the greatest change in
heart rate.
3) Why does the isometric exercise have a greater effect on MAP than the other
conditions? Why do the squats have a greater effect on HR?
Isometric exercises should have a greater effect on MAP than the others because
you are constantly contracting the muscles in the arms with the hand grip. Squats
have a greater effect on heart rate because the body is doing the most work with
the larger muscles so as a result, heart rate increases.