Heart Rate Lab Report

The Effect of Degree of Exertion on Percent Change in Heart Rate

Introduction: The main goal of the circulatory system is to circulate the blood around the body to supply oxygen and nutrients and to remove waste products. The heart, a hollow muscle that pumps blood through the blood vessels does this through repeated contractions. Each time the heart beats, deoxygenated blood is pumped through the pulmonary artery to the lungs where oxygen and CO2 are exchanged in the alveoli. As one inhales, oxygen moves from the alveoli to the surrounding capillaries into the bloodstream and CO2 moves from the bloodstream to the surrounding capillaries to the alveoli. As one exhales, CO2 is released from the lungs. Whether or not one is exercising, oxygen is necessary to complete cellular respiration in order to generate ATP. When exercise occurs, more oxygen is required by the body since more ATP is required. Therefore, the rate of cellular respiration increases. The effect of exercise on heart rate in beats per minute (bpm) was tested in this lab, with the percent change in heart rate being the marker for change. First, resting heart rate in bpm was recorded. Then an exercise was performed, with the exercises varying depending upon the group. After physical exertion was completed for a certain period of time, the heart rate in bpm was then recorded. If more exercise is done, then the heart rate will increase to a greater extent.

However, for a more informative graph, an average percent change was recorded for each degree of exertion. Even though it may seem that only three data points were recorded on the graph below, in actuality 18 sets of data points were recorded. However, all sets from each group were factored into an average for that particular degree of