How Does Exercise Affect My Heart Rate?

The apparatus that I will use to carry out my experiment consists of: a stopwatch, a pen, a pencil, a ruler and paper.

To get reliable and detailed results, when exercising and measuring the pulse of my heart rate for one minute, I will use a stopwatch/clock, by doing so, it increase the accuracy of the test. Furthermore, when I am regaining my resting heart rate for five minutes, I will also use the stopwatch/clock to precisely time the 5 minutes. It is important to keep the timing the same each time because a second either way can alter the final results causing it to be imprecise. I will exercise and record my heart rate for one minute each time, and for every exercise I will do this three times. Plus, after each exercise, I will rest for 5 minutes to recover my resting heart rate. Also I will after each exercise I will record my heart rate for one minute three times.

The important variables of the experiment are the change of the type of exercise completed each time. The first exercise will be walking, the following light logging and the last, hard running. I will perform these different types of exercises in a safe, open area such as a field.

I predict that my heart rate will increase the faster and harder the exercise is. This is because exercise or other increases in physical activity require muscles to work harder or faster. To perform, our muscles consume oxygen. As our muscles work harder or faster, they require more oxygen. This increased demand for oxygen causes changes in the circulatory and respiratory systems. Our respiration or breathing rate increases: we take more breaths per minute in order to get more oxygen into the body. Our heart rate increases: the heart beats more times per minute in order to pump the blood containing the oxygen to the muscles. As a result, the muscles receive more oxygen per minute. Our heart rate and respiration rate stay elevated as long as the muscles continue to need more oxygen. When we stop exercising, the heart rate and respiration rate gradually decrease because the muscles no longer need as much oxygen. Therefore I predict my resting heart rate will be the lowest, and then the walking, light jogging and my hard running heart rate will be the highest.

The measurements that I will use will be in seconds (s) and beats per minute (bpm) e.g. whilst running for 60s my heart rate was 180bpm.

To ensure safety throughout my experiment, I will make sure I am wearing shoes which have a rubber grip on the soles to prevent slippage while I am doing the exercises e.g. trainers. Also, if someone has an injury, bandages should be used to support and protect the injury.

After completing the experiment, I got the following results:

Table of results:

Type of Exercise carried out for 1 min.

Trial 1

Trial 2

Hea

Trial 3

Average

Resting

60

62

61

61

Walking

90

89

89

89

Light Jog

56

54

53

54

Hard Running

80

80

78

79

Line graph of results:

To ensure that all of my results are reliable and accurate I have attempted each exercise (walking, light jog and hard running) 3 times then taken an average by adding all three trials up and then dividing the total by three. I have taken an average to see if any of my results have been affected by any uncontrollable variables, therefore this would not affect my final result. Before each of my trials of exercising I have ensured that my heart rate is always at my resting rate in order so that this does not affect my results, so that my experiment is fair and my results reliable. To successfully accomplish my investigation, I used all the apparatus skilfully to get and record lots of reliable and useful results.

From my results graph and table I have found out that the harder and faster the exercise, the faster my heart beats per minute, and therefore the higher my heart rate. I have concluded that as the amount of exercise undertaken by a person increases the faster (higher) their heart rate will be. This is because when a person undertakes any movement or exercise they need oxygen to be taken in by the lungs and transferred to blood cells through the capillaries in the body and for the blood to transport the oxygen (and glucose) to all the body cells by being pumped around by the heart, so that they can use these two things in respiration (a reaction that takes place in every cell in the body) to produce water, carbon dioxide and most importantly energy so that the body muscles can do the necessary movement to do the exercise. When the exercise time is increased the need for oxygen to the muscles increases so that more respiration can take place to produce more energy for the muscles to work harder and for longer. For this to happen first the breathing rate increases.

I think that my investigation was successful and I feel that the results I got were reliable and accurate. I think that my results are quite accurate. This is because I used a stopwatch/clock to accurately measure all the times. I haven't got any results which look erroneous or wrong. What I would do if I redid the experiment to increase the accuracy even more would be to use a device which measures my heart rate continuously. This apparatus would probably be more reliable opposed to if I manually measured and recorded my own heart rate, and it would probably improve the consistency and I would therefore get better results. Apart from that I would think my results are reliable and accurate as there are no anomalous results.