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Introduction

Design an Experiment to show how exercise can affect Heart Rate in Humans Results: The experiment was carried out but prior to this a few modifications were made. Modifications: The time allowed for recovery was not between 2 to 4 minutes as planned, instead it was 5 minutes. Instead of using the stairs to carry out the experiment, we used a bench. A metronome was not used during the experiment. Results: * It was hard to always get the resting heart rate before each exercise and so instead we waited until the resting heart rate was within 5 beats/minute of the original one. * The resting heart rate was measured for 30 seconds, three times before the exercise whereas the finishing heart rate was measured once for 15 seconds after the exercise. These were made up to beats/minute as shown in the table of results. Number of Step Ups Heart rate beats/minute Average heart rate (beats/minute) 1 2 3 4 5 0 74.00 79.00 66.30 59.60 72.00 70.18 5 94.00 90.70 72.00 N/A 93.00 87.43 10 111.33 100.00 83.00 120.00 105.30 103.93 15 124.00 N/A N/A N/A 109.30 116.65 20 131.67 114.70 108.00 136.60 119.30 122.05 25 N/A N/A N/A N/A 125.70 125.70 30 142.00 126.00 130.70 141.70 130.00 134.08 35 N/A N/A N/A N/A N/A N/A 40 151.33 133.30 145.00 143.70 133.30 141.33 The set of results in bold indicate my results to the experiment, whilst the other results are the pool results. My actual results to the experiment are shown below. Number of Step Ups Heart rate beats/minute Average heart rate (beats/minute) 0 75.00 77.00 70.00 74.00 5 90.00 93.00 99.00 94.00 10 112.00 109.00 113.00 111.33 15 120.00 124.00 128.00 124.00 20 130.00 133.00 ...read more.

Middle

This is because the experiment was accurate and suitable enough to prove the main trend in that the heart rate increased as the amount of exercise carried out increased, but the results obtained could be more accurate and consistent. Firstly, the suitability and accuracy of the procedures undertaken and the consistency of certain variables will be discussed to find sources of error and how they can be improved or eliminated: * I believe that a major source of error and limitation in this experiment was the method used to take the pulse. Firstly, the pulse on the underside of the wrist was not always easy to find. This was a bigger problem when the pulse was taken for 15 seconds after the exercise as it was necessary to achieve a heart rate that was valid for immediately after the exercise and time may have been wasted finding a pulse and during this time, the heart rate would have fallen. Once found, the pulse was sometimes very weak or difficult to monitor and this would greatly have affected the results if mistakes were made here. It was also hard to keep track of the pulse at times as the heart beat so fast; this was especially true for the last step of the exercise with 40 steps. There is also ambiguity over the right amount of time during which the pulse should be taken. Before the exercise the pulse was taken for 30 seconds and after exercising it was taken only for 15 seconds. To achieve a more accurate heart rate in beats per minute, the pulse should be taken for a longer period of time, a minute maybe. ...read more.

Conclusion

However, the problem with these changes is that it is unrealistic that the people could do this much exercise. But the whole experiment could be split up into a number of days but the conditions under which the exercise is carried out (especially the temperature) could be maintained constant by making sure the exercise took place indoors and the heating in the room could be controlled appropriately. If the resting heart rate at the start of each day was the same, there should not be a major problem. But this could form the basis of an extension to this experiment in investigating how exercise affects heart rate in different conditions such as different temperatures. Another way to extend the investigation is to use people of different age, sex, fitness and health to monitor how the affects of exercise on heart rate vary. Different types of exercises could also be investigated, so that different muscles are used or more muscles are made to work harder and this may affect heart rate differently. In this experiment, only the amount of exercise was varied whereas the intensity remained constant. Further investigations could vary other factors of exercise such as the intensity or time while others are kept constant. Overall I was quite happy with the results of this experiment as the general trend was recognised and the results were quite accurate. But by improving the experiment in the ways mentioned earlier, I would hope to decrease the number of anomalous results and the deviation amongst replicates and gets the points on the graph even closer to the best-fit line and thereby increases the reliability and accuracy of the experiment. Expanding the experiment considerably would also make it more suitable and allow a more thorough examination of how exercise affects heart rate. Anish Amin L6AJWH ...read more.

This student written piece of work is one of many that can be found in our GCSE Humans as Organisms section.