We will expect some difference between lying down and standing up.
Afterwards we will start doing some exercise stepping up and down on a chair. We will do 20 steps and then we will measure the pulse rate. We’ve chosen to count the steps instead of stepping up and down for one minute because we see it will make the experiment fairer, yet, each person would do a different amount of steps in that minute. After doing exercise we will rest one minute because at the end of the experiment we want to see how does the pulse rate changes doing more or less exercise.
We will repeat the same as before but now we will do 40 steps. Then we will measure the pulse rate and record it and rest for another minute whilst my partner does the exercise.
The last exercise will be doing the same thing with the chair but know we will increase it to 80 steps. We will follow the same method as before.
Prediction
Exercise makes the heart beat faster, bringing more blood to the muscles. In a healthy adult we know that the heartbeats should be an average of 72 times a minute although this can vary(60-80beats).
When you are at rest your pulse should be normal, about 72 beats/m. Immediately after exercise your pulse rate will increase considerately because the heart needs to pump faster to give more oxygen to your body.
If you don’t continue doing exercise you will see that your pulse rate decreases and goes back to normal.
We’ve decided to test your pulse rate when you are standing up and when you are lying down because there may be a difference. This is because when you are lying down your heart doesn’t need to pump as faster as when you are standing up yet is more hard work to push things up than to go straight.
In our experiment we should see a difference between the different periods of exercise, the pulse rate should go faster at the end, and also a difference between lying down and standing up.
CONCLUSION
The results demonstrate what I predicted which was that after 30 s lying down my pulse rate would be lower 62-60 than after 30 s standing up 67-69 because blood flows easier when you are in a horizontal position than if you are vertical.
When doing exercise each time I did more steps my pulse increase considerately due to the amount of exercise I was doing. I used a chair to do the steps which was 45cm high, which was quite tall because at the end I was exhausted. After doing 20 steps I recorded my pulse rate in one minute time. In that minute my pulse rate increased a lot, I had 104 beats/m. Then I did 40 steps taking my time, although without stopping, with a constant rhythm. I did one minute rest after that and my pulse had increased very little just two beats /m more. The last 80 steps I was completely out of breath and my pulse rate reaches 130b/m which is quite good because it means that although I did exercise I am quite fit.
EVALUATION
The experiment hasn’t been a very fair test due to numerous complications in nature. The menstruation cycle is one variation which can alter the pulse rate as well as when you are anxious, nervous etc because the heart needs to pump quicker which means the pulse rate increases. Maybe I did less exercise than other people in my class and that’s why I had less pulse rate than them or it is because I am fitter. The maximum beats per minute a teenager can have normally is 205 b/m. If I had done a graph of my results I could see if I was fit or not because when pulse rate decreases rapidly it means you are fit whilst if there is a slow recovery you are not as fit as you should.
