Safety
I will do a number of things to make sure my experiment is safe.
I will make sure that I am wearing trainers, as otherwise I will hurt my ankles. I will also make sure that the step is on flat floor.
Prediction
I predict that my pulse rate will increase as I do more exercise.
Explanation of my prediction
The amount of exercise a person does will effect the pulse rate. For example, more exercise means more movement so more energy will be needed. In order to get more energy; respiration needs to take place at a faster rate. More oxygen is used so more carbon dioxide is produced. Carbon dioxide is a waste product and it must be removed, as it is a toxin. Because of the extra carbon dioxide being produced, blood is pumped around the body faster in order to transport it. This process will give you a faster pulse rate.
When a person does vigorous exercise their body can’t always supply enough oxygen to their muscles. When this occurs the muscle will start doing anaerobic respiration. Anaerobic means without oxygen, it is the incomplete break down of glucose. Anaerobic respiration is less efficient than aerobic respiration. Oxygen is needed to break down lactic acid to carbon dioxide and water.
After anaerobic respiration oxygen is needed to get rid of the lactic acid, this is called the oxygen debt. This is why your heart rate stays high and it takes a while to get your breath back after you have stopped running - oxygen is still being delivered to the muscles to oxidise the lactic acid into CO2. The fitter you are, the quicker you recover.
Results
Conclusion
I noticed that as I increased the amount of exercise that I did, my pulse rate increased also. My pulse rate increased at a fairly steady rate, going up by roughly 10 beats per minute, until four minutes when it began to increase by less beats per minute.
My graph tells me that as the minutes of exercise increase so does my pulse rate. The graph shows that by doing five minutes of exercise, it is not likely that I have reached my maximum pulse rate.
My results show that by increasing the amount of exercise, my pulse rate increases also. As more exercise is done, respiration has to take place at a faster rate to keep up with the bodies need for oxygen. Blood is pumped around the body faster to transport the waste carbon dioxide, this means the pulse rate will increase. My results fit in with my prediction. I was breathing more deeply and therefore taking in more oxygen. As I was using more energy, the body needed more oxygen for respiration to take place. The blood is pumped around the body faster to get rid of the waste carbon dioxide therefore giving me a faster pulse rate. The body works harder to remove Carbon dioxide because it is a toxin and will cause cramp.
Evaluation
I think that my experiment was accurate. I repeated the experiment three times and worked out the average answer. All my results followed a trend and I didn’t get any anomalous results. I also let my pulse rate return to normal in between each reading. I kept the step at the same height and the same person took the time for me. I feel that my procedure was suitable because I thought about my plan and followed it carefully. I also repeated my experiment three times to make sure that my results were not anomalous. I don’t think I collected enough evidence to draw any film conclusions. To do that I would have to extend the amount of exercise time, that way I may find some patterns that won’t have developed after only five minutes of exercise. I would also have to do more than three tests to improve the accuracy of my final results. This would give me more accurate results. I could also extend my investigation by investigating the breathing rate and perspiration rates and see how they relate to each other.
