The Effect of Exercise on Blood Pressure
Picture of the student researcher

Researched by Kierea M.


The purpose of this experiment was to compare the resting blood pressure of 6th grade boys and girls and determine the change in blood pressure caused by mild exercise. 
I became interested in this idea while I was at basketball practice.  My team (a girls’ team) was doing lay-ins as were the boys’ team on the other side  I wondered whose hearts would be working harder doing the same exercise, girls’ or boys’. 
The information gained from this experiment could be used to help doctors and medical health employees to know what types of changes certain kinds of exercises have on blood pressure of grade school students. 


1. My first hypothesis was that 6th boys’ blood pressure would be higher than 6th grade girls’ blood pressure while resting. 
2. My second hypothesis was that after exercising 6th grade boys’ and 6th grade girls’ blood pressure would both increase. 
3. My last hypothesis was that the blood pressure when exercising would be greater for 6th grade boys than 6th grade girls.

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I based my hypotheses on Mayo Clinic Family Medical Health, that states, that high blood pressure occurs more in men then women until around middle age.


The constants in this study were: 

  •  The subjects were used in the resting and exercising experiment.
  • The number of subjects of each gender.
  • The approximate age of subjects.
  • Time blood pressure is taken.
  • The time spent exercising (step test).
  • The time spent resting.
  • The type of exercise.
  • The type of instrument used to take blood pressure.
  • Position of subjects while taking blood pressure.
  • Temperature of room during testing.

The manipulated variables were the gender and the exercise.

The responding variable was the blood pressure. 

To measure the responding variable I used a Portable Wrist Blood Pressure Monitor placed on the wrist and recorded the blood pressure in millimeters of mercury. 

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1 sphygmomanometer
30 subjects
1 adult supervisor
1 area/room for testing
1 Instruction script for experimenter
1 stop watch

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1. Gather the materials. 
2. Obtain your subject volunteers.
3. Have one subject at a time come to experimenting location.
4. Have subject sit down and rest for three minutes.
5. While subject is resting, explain how the procedure will go and what he/she will be doing.
6. Show the subject how to use the blood pressure monitor.
7. Take subject’s blood pressure.
8. Have subject rest for three more minutes.
9. Take second resting blood pressure test. 
10. Have subject begin exercise and continue it for three minutes.
11. Take the subject’s blood pressure, subject must be in a sitting position
12. Have the subject begin exercising again for three minutes.
13. After the exercising take subject’s blood pressure.
14. When all is done, send subject back to class or the location he or she came from.
15. Repeat steps 1-10 on each of the other subjects

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The original purpose of this experiment was to compare the resting blood pressure of 6th grade boys and girls and determine the change in blood pressure caused by mild exercise.
The results of the experiment were that the 6th grade male’s and female’s blood pressure were both increased by exercise.  The Systolic increased 13 points on average, while the diastolic increased 5 points on average. Males and females did not have the same blood pressure readings, but there were no clear pattern showing one group is always higher or lower than the other.

See the data and graphs.


My first hypothesis was that 6th boys’ blood pressure would be higher then 6th grade girls’ blood pressure while resting. 
 The results indicate that this hypothesis should be rejected the female’s systolic blood pressure was slightly higher than the boy’s, but the male’s diastolic blood pressure was slightly higher than the girl’s.
My second hypothesis was that after exercising 6th grade boys’ and 6th grade girls’ blood pressure would both increase.
The results indicate that this hypothesis should be accepted, the girl’s had a larger systolic blood pressure increase and the boy’s had a larger diastolic blood pressure increase, but both increased
My last hypothesis was that the blood pressure after exercising would be greater for 6th grade boys than 6th grade girls.
The results indicate that this hypothesis should be rejected because the girl’s blood pressure had a higher systolic than the boy’s and the male’s had a larger diastolic blood pressure.

Because of the results of this experiment, I wonder if the same results would occur for age groups of people in their thirties, forties, fifties or sixties. I also wonder if a more vigorous would increase blood pressure more. 

If I were to conduct this project again I would have a medical specialist show me how to use a sphygmomanometer and use one while I was conducting my experiment the "Portable Wrist Blood Pressure Monitor" seemed to give questionable readings at times.  I would also conduct more trials and use more subjects in the experiment to have more reliable data. I would use a different exercising method like using an exercising bicycle, also. 

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Research Report

Health is one of the most important factors in living a long and happy life. The circulatory system plays a very significant role in making that happen. 
Circulatory System 
 The circulatory system is a network that carries blood throughout the body.  It supplies cells with the food and oxygen they need to survive. It also carries waste and carbon dioxide away from cells and helps regulate the body’s temperature.  The circulatory system carries substances that help fight disease and another substance called hormones that help activate the body’s system.
The circulatory system consists of three main parts; the heart, the blood, and the blood vessels throughout the body.  The heart consists of two pumps that lie side by side. The left pump is the stronger pump of the two. It receives blood from the lungs and sends it to cells throughout the body. The weaker or right pump receives blood from cells and transports it to the lungs. The septum divides the heart into two sections lengthwise and the valves divide the heart into two sections, the top and bottom.  Each side of the heart has two chambers, one above the other. There is a thin membrane called endocardium that lines both chambers.  The top chambers or the right atrium and left atrium receive and store blood that is returning to the heart through veins. After the atrium (atrium plural) is filled with blood, it squeezes the blood into the lower chambers, the right and left ventricles. When the ventricles fill with blood they pump it out of the heart to other parts of the body through arteries.  The ventricles are bigger and stronger than the atria.
 Another part of the circulatory system is the blood vessels. Blood vessels are a complex system of connecting tubes throughout the body. There are three types of blood vessels; arteries, veins and capillaries. Arteries carry blood from the heart, veins return blood to the heart and capillaries are tiny vessels that connect arteries and veins. 
The last part of the circulatory system is the blood.  It consists of a liquid called plasma, which is made mostly of water, but also consists of minerals, protein, and other substances. In blood there are three solid particles, usually referred to as the three elements. The three elements are red blood cells, white blood cells and platelets. Red blood cells carry oxygen and carbon dioxide.  White blood cells protect the body from disease and platelets release substances so blood doesn’t clot, platelets also prevent the body from blood loss if a vessel is injured.

Blood Pressure
 Blood pressure is the measure of pressure or tension of the blood as it pushes against artery walls.  It usually becomes higher with age.
As you can see in the table below, high blood pressure or hypertension can be very severe.  It may cause strokes and is able to lead to death if it is high enough. It is also known to cause blurry eyesight. You should also be careful about keeping your blood pressure stable and not too low. Low blood pressure or hypotension can be just as severe as high.  It also may lead to death.  Be sure to get your blood pressure taken regularly because studies have shown that severe high or low blood pressure symptoms may not show up until years later. 

Blood Pressure
(mm of Mercury) Diastolic 
(Mm of Mercury)
Normal 120-130 80-85
High Normal 130-139 85-89
Mild 140-159 90-99
Moderate 160-179 100-109
Severe 180-209 110-119
Very Severe 209 or more 119 or more

There are two types of blood pressure, systolic and diastolic.  Systolic blood pressure is the blood pressure generated by heartbeat or while the heart muscle is contracting. It is the higher blood pressure. Diastolic blood pressure is the blood’s pressure between heartbeats or while the heart is resting. It is the lower pressure. I
Blood pressure is measured in millimeters of mercury.  An average blood pressure for adults is 120/80.  The first number 120mm is systolic blood pressure. The last number 80mm is diastolic blood pressure.
To take blood pressure many medical employees use a medical instrument called a sphygmomanometer. How it works to use a sphygmomanometer you wrap the cuff around the patient’s arm on the biceps just below the elbow. You should be able to hear the arteries pulsate. Air is then pumped into the cuff, causing the cuff to squeeze the arteries in the arm, which stops the blood flow, the sound then stops. Now, air is slowly let out of the cuff. When the pressure of the cuff is lower than blood pressure, the blood flow returns. While the blood flow is resuming it is called Systolic pressure.  When more is air lets out of the cuff, the instrument makes a muffling noise that is the diastolic pressure.
 Another instrument sometimes used to measure blood pressure is a "Portable Wrist Blood Pressure Monitor"; this instrument is very simple to use. It is similar in some ways to an automatic sphygmomanometer.  The first thing you do while using it is to wrap the cuff around the patient’s wrist tightly so it will not move during the testing, it should be as evenly centered as possible. Make sure while putting the instrument on the subject, they have their palm up. Before you start the process of actually taking the blood pressure, have the patient sit down and have the blood pressure monitor about even with the height of his or her chest. The "Portable Wrist Blood Pressure Monitor" is electronic so all you need to do is press "on", wait for a zero to show up on the screen and press "start". This instrument will then tighten, stopping the blood flow, after a short time it will automatically release the pressure slowly and show the reading of the blood’s pressure. The systolic blood pressure reading will be the top number and the diastolic blood pressure will be the bottom number. 

Staying in shape is a good way to maintain a healthy heart and control your blood pressure.  Body size has no apparent relationship with the measurement of blood pressure, so no matter what size you are it is very important to exercise to keep your body healthy and your blood pressure down. 
 There are some differences in blood pressure due to gender. Females usually have higher blood pressure than males from the time they are young adults to middle age, then the process seems to reverse. So, usually after middle age the average female’s blood pressure will be lower than an average male’s blood pressure. 
 An unhealthy heart is a huge health risk. Check your blood pressure regularly so you can know and control your blood pressure and keep a healthy heart.

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Crawford, Michael H. "Heart." World Book Encyclopedia, 1999, pg. 132-135.

Joint National Committee on Detection. " Blood Pressure Classifications." 11-14-2001

Kalsher, Stanley. "Blood Pressure." Academic American Encyclopedia, 1999. Pg.236

Larson, David E. M.D (Editor in Chief). Mayo Clinic (Family Health Book). New York. William Morrow and Company, Inc, 1996. Pg684-650

Marks, Barbara.  Family Health Medical Guide. U.S.A. 1989. Pg. 80, 135, 306, 387.

Rieck, James Nelson. ‘"Glucose." World Book Encyclopedia, 1999.

Sabatino, Dominick. "Blood Pressure." World Book Encyclopedia, 1999. pg. 416.

Weisberg, Martin. "Circulatory System." World Book Encyclopedia, 1999. pg. 559.


I'd like to thank all of the following people for helping and supporting me during my experiment

  • I'd like to thank my family for always supporting me in everything I do and transporting to and from after  school work classes.
  • Dr. Wolf for giving me tips on my experiment.
  • The IRB commitee for making sure my experiment was safe.
  • All of the people who particapated in my experiment because without them none of this would be possible.
  • Mrs. Helms for helping me  with my experiment.
  • Mr. Newkirk for helping me obtain all of my supplies for my project and experiment.


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