I am going to investigate my bodies heart rate when I exercise for certain fixed amounts of time.

INTRODUCTION:

Blood is fluid that circulates in the arteries and veins of the body. Blood is bright red or scarlet when it has been oxygenated in the lungs and passes into the arteries; it becomes bluish red when it has given up its oxygen to nourish the tissues of the body and is returning to the lungs through the veins and the tiny vessels called capillaries. In the lungs, the blood gives up the carbon dioxide wastes it has taken from the tissues, receives a new supply of oxygen, and begins a new cycle (this happens at a fast rate whilst exercising). This movement of blood is brought about by the coordinated activity of the heart, lungs, and blood vessels.

The heart is the organ that pumps the blood and circulates it around the body. The circulatory System is the course taken by the blood through the arteries, capillaries, and veins and back to the heart. In humans, the heart is made up of four chambers: the right and left auricles, or atria, and the right and left ventricles. The right side of the heart pumps oxygen-poor blood from the cells of the body back to the lungs for new oxygen; the left side of the heart receives blood rich in oxygen from the lungs and pumps it through the arteries to the various parts of the body. It is estimated that a given portion of the blood completes its course of circulation in approximately 30 seconds.

The breathing system plays a major part in exercising, the muscles need oxygen to release energy and this can be brought to the muscles from the blood. But when you breathe you actually inhale oxygen and then that oxygen goes into the blood to be carried to the muscles. As you exercise more vigorously more oxygen is needed for the muscles so you have to breathe at a faster rate. And your heart also has to beat at a faster pulse. This is so the blood can pump the oxygen to the muscles quicker. The muscles also need glucose to produce energy. This comes from the food you eat. And the blood can absorb it from the small intestines. Cells respire by taking in oxygen and glucose, and gives out carbon dioxide and water.

Although skeletal-muscle contraction is a main feature of exercise, many other systems in the body are activated to support this process. The heart pumps increased volumes of blood to supply oxygen and nutrients and remove carbon dioxide and metabolic wastes. The respiratory system handles a big workload, exchanging oxygen and carbon dioxide between the blood and the air.

This is a preview of the whole essay

Exercise is activity that results in contraction of muscles. The term is usually used in reference to any activity that promotes physical fitness. Although muscle contraction is the common element of all forms of exercise, many other organs and systems are affected, for example, the heart and lungs. During respiration the cells work harder and quicker as well. To make the intake of oxygen and glucose and the giving out of carbon dioxide and water process quicker.

Heart rate is usually measured with a heart monitor. I am going to measure my heart pulse and you measure that by feeling for your pulse under your thumb. I opted this because it is easier and you don’t need any equipment to do it. Heart monitors are expensive and hard to get hold of.

I am going to choose to measure my heart pulse. So I am going to measure how many times my heart beats in a minute in various different scenarios. I am going to measure my heart rate by counting it for 15 seconds and then times the result by 4. This is because if I measured it for a whole minute after exercise then my heart rate would start steadying to its usual rate and my results would be slightly inaccurate. I have tried as part of my preliminary investigation, which back this up. When I did it for 15 seconds and then times it by 4 I found that it turned out that if I did it this way then it is 8 beats more a second than if I measured my heart rate for a whole minute.

EXERCISE: I am going to choose step ups on a step 1 foot above the ground. I am going to do 1 step up every 2 seconds.

PRELIMENARY RESULTS:

In my preliminary results I measured my heart pulse after exercise for different times and then times them to make it equal to a minute to prove my prediction that your heart pulse will start to steady back to a normal rate if you measure it for a whole minute. This would happen because the muscles have stopped being worked hard so they don’t demand as much so the heart will start to beat slower. These are my results.

VARIABLES:

The variables for this experiment could be:

1. type of exercise-because some exercises are a lot more tiring than others so if you were doing a strenuous exercise such as sprinting for 30 seconds your heart pulse would be a lot faster than if you did sit ups for 30 seconds.

2. fitness of person-because some people are fitter than others so there would be different levels of heart rate. The difference is that the fitter person would find that their heart pulse after exercising is lower than that of a person less fit than them.

3. sex-because the fitness of the two sexes are rarely the same. The difference varies but there is a distinct difference between the two sexes because often the male has a larger lung capacity and stronger muscles so exercise is easier for them. This is not always the case sometimes it could be the other way round but the end heart pulse is rarely the same.

4. time of day-because if you do the exercise at the end of the day then you will be very tired and not have as much energy as earl morning. If you don’t have as much energy then your heart it going to have to work harder to ensure the muscles get enough energy, this will mean to beat faster and have a higher heart pulse.

5. atmosphere-simply because it depend what sort of atmosphere you do the exercise in. if you do exercise up a mountain then there is less oxygen in the atmosphere so you breathe less oxygen in at a time. This will mean that the heart will have to work harder to ensure it gives the muscles the amount of oxygen they need, this will mean beating faster so the heart pulse will rise.

6. length of time exercise is done for.-because if you do an exercise for a long time then your heart pulse will go up and up until it can’t beat any faster and you will have to slow down or stop.

The variable I have chosen to investigate is the length of time that you exercise for. I chose this because it will be an easy and effective investigation. I am going to measure the effect the exercise has on my body by measuring how many times my heart beats in a minute after exercising for different lengths of time.

I am going to keep everything other than the length of time I do the exercise for the same. I will stick to the same exercise all the time and ensure I do it the same amount of times per second. I will always do it at about the same time of day. I will always wait for my heart pulse to go back to my resting rate before I try another length of time. I will always be doing it in the same atmosphere because I will always do it in the same room. I will complete the investigation within a week in case my fitness level gets better or worse and this will effect my results. All these variables I will keep constant to ensure a fair test.

PREDICTION:

I predicted the line to start steeply rising at the start because the muscles will start to demand more and more oxygen and glucose. The only way this can happen is for the blood to transport it to the muscles quicker and the only way that can happen is for the heart to beat at a faster pulse. As I exercise for over 3 minutes I predicted that the line would start to level out. This is because it gets to a stage where your heart can’t beat any faster so it stays about the same pulse. The muscles need this oxygen and glucose to contract and respire. So the quicker the oxygen and glucose gets to the muscles, the quicker your muscles can work and the more powerful they are.

APPARATUS: a step (to do the step ups on), a stopwatch and a calculator.

SAFETY: When you start the physical part of the investigation you need to make sure you are a fair distance away from everyone else. You should also make sure you don’t exercise immediately after you have eaten to avoid indigestion. Work with a partner so if you fall over he can help you.

METHOD:

Set up the apparatus and ensure you take the safety precautions stated above.
Measure your pulse with two fingers on your wrist just below your hand.
Measure your pulse whilst relaxing for 15 seconds (using a stop watch), then times your result by 4.
Do the step ups every 2 seconds for 30 seconds then measure your pulse for 15 seconds and times your result by 4.
Do the step ups every 2 seconds for 1 minute then measure your pulse for 15 seconds and times the result by 4.
Do the same as in 4 and 5 but exercise for 1.5, 2, 2.5, 3, 3.5, 4, 4.5 and 5 minutes.
Record all results.
Redo the whole investigation 2 more times to check your results are the same (if your result are similar then you can assume they are reliable) and make an average.
Display your results in a line graph form.
Pack away your apparatus.