The heart is a muscle that is used to pump blood throughout the body and helps circulate oxygen and red blood cells to muscles and organs. Heart rate is the measure of how many times a person’s heart beats in a certain amount of time. Its is measure in BPM(beats per minute). This can be affected by the work of the muscles in the body. The more strain the muscles of the body are under or the more work they do means a higher heart rate. Recovery rate is derived from the measuring the heart rate after ceasing activity.
The hearts need to speed or down is triggered by the cell’s need for oxygen. As one exercises, the muscles in the body need ATP so they can complete their respective functions. ATP in the energy source for the cells and it is required for the cell to do work. Oxygen is the final electron acceptor in the cell’s production of ATP and is therefore required to make energy for the cell. Therefore, the tissue cells need oxygen to create energy and need energy to complete their functions. They get the oxygen from oxygenated blood circulating throughout the body. The oxygenated blood is pumped from the left ventricle of the heart to the aorta and then throughout the body. Once this oxygenated blood is used by tissues it is sent back to the heart as deoxygenated blood to the right atrium and then to the right ventricle. From here the blood travels through the pulmonary circuit and becomes oxygenated again through the oxygen breathed in by the lungs. The blood is oxygenated again and repeats through the circulatory system. This system contains the heart, blood vessels, and blood that circulates throughout the body and delivers nutrients and other essential materials to the cells. It also removes waste products. The more muscles work, the more oxygen they need which means the circulatory system must compensate and pass more oxygenated blood through to the muscles which need it to make energy. Therefore, the heart must work faster to pump this blood throughout the body at a faster pace, which increases the heart rate. The lungs also play an important role because the oxygen breathed in oxygenates the deoxygenated blood. This means that the lungs must also work harder when exercising because the blood needs to be oxygenated faster since the muscles are working harder and need the ATP. This applies mainly to exercise however; stress, medication, infections and even stimulants such as caffeine can also affect heart rate.
Voltage is the electrical force that would drive an electrical current between two different points. When applied to the human circulatory system, it refers to “The depolarization and repolarization of the SA node and the other elements of the heart’s electical system produce a strong pattern of voltage change which can be measured with electrodes on the skin.” This is referring to the positive and negative ions. The SA node refers to the pacemaker which has to do with the hearts ability to generate its own impulse. The AV node also plays a role in this process and is found at the cross section between the right atrium and ventricle. These control the atrial and ventricular contraction which is essentially the heartbeat.
This lab utilized an ear clip to measure the heartbeat of the subject. The clip has an infrared light source and a light detector. The detector measures light transmitted from blood after light is emitted from the infrared source. The light sensor measure the change in the light transmitted. The reads your pulse because the amount of light emitted is different during high blood flow compared to low blood flow.
The heart, like any other muscle in the body, requires exercise to keep it in healthy condition. Daily cardio exercises can help a person lower their resting heart rate which means the heart needs less beats per minute because the muscle has become stronger. Therefore, the heart will become more efficient and pump more blood out with each beat as it gets stronger. This means the heart a heart can return to the resting rate quickly after strenuous exercise, meaning the recovery rate will be higher as the heart strengthens. Most people range from 60-100 BPM. Males average around 75 BPM and woman average around 70 BPM.
During the exercise, I had to begin breathing quickly and my muscles began to get tired in my legs after about 30-45 seconds. This continued throughout the exercise time period of 2 minutes. My heart rate also began to increase and I noticed a rise in body temperature because I began to sweat and I could also see my veins filling with more blood on more arms as I saw them stick out more.
After the exercise I noticed I was tired overall and after I sat down the heart rate began to decrease steadily. I also became less tired and slowed my breathing down once I sat down on the chair.
Heart Rate Data
Heart Rate at Rest vs. Heart Rate After Exercise
Recovery Rate Calculations
Max heart rate after exercise – min heart rate after exercise
167BPM – 136BPM = 3.1 = Good
Overall, the heart rate after exercise was well above the heart rate at rest as one can see from the graph above. However, the graph above does have 2 outliers of 200 BPM which must have been due to an error in the machine because it would not be possible for the heart rate to increase that rapidly for no reason. The mean also shows this as the mean at rest was 96 BPM , but after exercising the heart rate mean was 151 BPM. The trials resulted in a good recovery rate of 3.1. This was found by subtracting the max after exercising which was 167 BPM and then subtracting it by the min after exercise which was 136 BPM. There are several factors in my lifestyle that may have affected this including my diet and exercise. I exercise moderately at the gym, but overall I do more exercises that include lifting which are not cardio exercises. I do not play any sports which may also have affected the recovery rate. I say I healthy and drink a lot of water and overall I would consider myself in good shape, but I also am not very muscular. I was in no way nervous and drink caffeine on occasion, but did not the day or week of the lab. These factors all may have contributed to a good recovery rate of 3.1.
The objective of the lab was to determine the effect of exercise on a human’s rate and this objective was met through completion of the lab. This was accomplished through measuring the heart rate at rest and then measuring the heart rate after exercising. One can clearly see the difference as the mean for the heartbeat at rest was 96 BPM while the mean after exercise was 151 BPM. The minimum and maximum of the graph is skewed because of errors in the machine. The heart rate must increase when the body is using energy and working harder. This supports the hypothesis that the heart rate will increase after exercising compared to the heart rate at rest. These results occurred because the muscles were in need of more oxygenated blood than at rest, so it could make more energy to complete the exercises. The heart therefore needed to pump the blood faster to the muscles which increases the heart rate.
One large source of error is the error in the machine itself as well as the error in the clip attachment. The machine itself is not as accurate as machines like electrocardiograms and makes many mistakes. The clip itself is also a source of error because it slipped off several times which made huge errors on the machine and is evident in the graph. At both 5 seconds and 22 seconds the clip slipped causing huge outliers in the graph both being at 200 BPM which is impossible to jump from out of nowhere especially when at rest. An improvement that could be made would find a way to keep the ear clip from slipping off the ear. This might be able to be done with tape.
This lab could help in the future if one were to use a more advanced and expensive machine such as an electrocardiogram. Both are the same idea of measuring the heart rate, but the electrocardiogram is much more accurate because it measures skin electrodes instead of lift reflection. A similar experiment could be performed with exercising but it could be done while exercising instead of only after exercising.
What was the control in the experiment?
The control of the experiment was the resting heart rate. This heart rate would be compared to the heart rate after exercise.
How does the resting heart rate compare to the rate after exercise?
The heart rate is much higher after exercise compared to the heart rate at rest. This is because the muscles are being used more and need more oxygen during exercise. Therefore the heart needs to pump more oxygenated blood to the muscles, increasing the rate.
When did the maximum heart rate occur?
My maximum heart rate was at 5 seconds and 22 seconds into the resting period which was clearly an error in the machine. Disregarding this error, the highest heart rate was at the beginning of Trial #2 which was after exercise and steadily declined from there. This makes sense because the muscles where working their hardest at this period and needed the most oxygenated blood at that point. Therefore, the heart would need to pump the most at this point leading to the highest heart rate.
Why, on a cellular level, does heart rate increase with exercise?
When the muscles are being worked, they require more oxygen to complete this work. The red blood cells that have hemoglobin that mainly carry the oxygen supply the muscles with the oxygen. Once, they deliver the oxygen, the blood is considered deoxygenated and is returned back to the heart. The heart in turn moves this blood to the pulmonary circuit which oxygenates the blood. This blood is then pumped throughout the body which is the beginning of the cycle once again. This all requires the pumping of the heart. The more muscles are worked throughout the body, the more oxygen they need which means the heart must pump more to compensate for the oxygen being used faster by the muscle.
Research to find out how heart rates & recovery rates differ between males & females.
The heart rate of male is slightly higher than the heart rate of a female because males have more muscle throughout the body. Therefore, they have more muscle that needs oxygen, meaning the heart needs to pump more oxygenated blood to the muscle. There is no difference between the recovery rates.
Research the differences in heart rates & recovery rates between athletes & non athletes.
An athlete’s heart muscle has built up overtime and become stronger due to the constant exercise an athlete participates in. Therefore, the heart muscle can pump more volume of blood per beat than a normal person. Therefore, their heart needs less beats to pump the oxygenated blood to the muscles in need of it. An athlete’s heart will also have a much higher recovery rate because their heart will be strong enough to easily handle the pace it needs to keep up with during exercise. It will then move down quickly to normal heart rate once the body is done exercising.