Kristin McKeown
Abby Side
Class Period 7
16 February 2012
The Effects of Different Exercises on Heart Rate
Introduction:
Problem/Question:
How does increasing the intensity of exercises affect the rate of the heart?
Background Research:
The circulatory system is essential to human life. Blood is carried from the heart through
arteries and to the capillaries. When blood reaches the capillaries, nutrients and oxygen will
diffuse out of the capillaries and into cell tissues. The blood however, gains carbon dioxide and
keeps its circulation moving, by proceeding through the veins, which returns the blood back to
the heart. This process then begins again at another heartbeat. Oxygen is required in order for the
person to perform cellular respiration. Cells need glucose and oxygen in order to produce ATP,
energy to do work. If someone begins to exercise and gradually increases the intensity of the
workout, the heart will pump faster, because it is requiring more oxygen to go to the muscles.
Hypothesis:
If one performs rigorous exercise for one minute, then their heart rate will be faster rather
then when resting or doing moderate exercise, because more oxygen is required for cellular
respiration.
Independent Variable:
Change in exercise.
Dependent Variable:
The rate of the heart.
Experimental Design:
Control Group:
Resting heart rate.
Experimental Group 1:
Moderate exercise.
Experimental Group 2:
Rigorous exercise.
Constant Variables:
Using the carotid pulse to determine the heart rate every time and not mixing between the
carotid and radial pulses, and timing for exactly one minute while resting, doing moderate, and
rigorous activities.
Lab Safety Precautions:

Be sure to have plenty of room while performing pulse-raising activities.

Avoid crashing into other classmates, or objects.

Do not push yourself to do the most strenuous activities.
Materials:

Stopwatch

Calculator

Access to stairs
Procedure:
1. Before beginning the experiment, be sure there is enough room around yourself in order
to prevent any accidents.
2. Using the index and middle fingers, locate the carotid pulse within the neck.
3. Begin the stopwatch for one minute, counting the number of pulse beats.
4. Record data.
5. Then, begin the stopwatch again for one minute, and during this time walk up and down
the stairs until the minute has passed.
6. Locate the carotid pulse and count the number of beats for another minute, using the
stopwatch.
7. Record data.
8. For the rigorous activity, being doing squats for one minute, using the stopwatch.
9. After the minute has passed, locate the carotid pulse and count the number of beats within
a minute.
10. Record data.
11. Repeat steps three through ten for trials two and three.
Results:
As the intensity of each excericse increased, the heart rate did as well. During trial one,
the resting pulse rate was 61 beats per minute, in trial two the heart rate was 59 beats per minute,
and in trial three for the resting heart rate was 61 beats per minute. The resting heart rate for the
most part stayed relatively around the same amount of beats per minute, there was no exercise
being performed that called for a lot of oxygen. For trial one of the moderate exercise, which was
walking up and down the stairs for one minute, was 95 beats per minute, in trial two 89 beats per
minute, and in trial three 91 beats per minute. The moderate exercise heart rates were higher than
the resting heart rates, but yet lower then the rigorous exercise heart rates. In trial one for the
rigorous exercise which was performing squats for one minute, was 104 beats per minute, in trial
two 95 beats per minute, and lastly in trial three 108 beats per minute. It is clear that the rigorous
exercise called for more oxygen to be brought to the muscles inside of the body, therefore
increasing the hearts rate. The average for the resting pulse was 60 beats per minute, for
moderate exercise 92 beats per minute, and lastly for rigorous exercise 103 beats per minute. In
conclusion, rigorous exercise increased the hearts rate to be faster then when resting or
performing moderate exercise.
Conclusion:
1. Our hypothesis was, if one performs rigorous exercise for one minute, then their heart
rate will be faster rather then when resting or doing moderate exercise, because more
oxygen is required for cellular respiration. Our hypothesis was proven to be correct by
the data collected from the experiment. As the exercises gradually became harder, the
heart rate was shown to increase. According to the averages, the resting heart rate was 60
beats per minute, the moderate exercise heart rate was 92 beats per minute, and the heart
rate for rigorous exercise was 103 beats per minute.
2a. Two specific molecules that the circulatory system could transport to the muscle tissues
to be used are glucose and oxygen. Both of these molecules are the starting substances for
cellular respiration. With these two molecules combined, ATP, water, and carbon dioxide
will be created. ATP, will then be used to be the energy substance in order to do work.
2b. Two specific molecules that the circulatory system could transport away form the muscle
tissues are water and carbon dioxide. These two molecules are the resulting products of
cellular respiration. The muscle tissues would not need these substances in order to do work,
because they would only require oxygen and glucose, the starting products of cellular
respiration.
3. The circulatory and respiratory systems are usually combined into the cardiopulmonary
systems because they both rely on each other. The heart pumps blood through the left and
right pulmonary arteries to reach both the right and left lungs. Once the deoxygenated blood
reaches there, gas exchange occurs. The capillaries diffuse out any waste products that are
not necessary for the blood. The new, oxygenated blood then flows through the left and right
pulmonary veins, back to the heart, where this process will repeat again.
4. If blood pressure were to be measured instead of heart rate, then the graph would still look
similar. It would look similar because both blood pressure and pulse are the pushing force of
blood through out the body.
Raw Data:
The Effect of Exercise on Heart Rate (pulse: beats per minute).
Trial
Resting
Moderate Exercise
Rigorous Exercise
1
61
95
104
2
59
89
95
3
61
91
108
Average
60
92
103