Prediction
I predict that as the body exercises the heart rate will increase. My reasoning behind this is that, as the body exercises the muscles need more oxygen. If the muscles need more oxygen this means that blood must be pumped faster (blood carries the oxygen to the cells) and the only way that it can be pumped faster is through more beats of the heart thus requiring an increased heart rate.
Method
Place a bench on the floor that should be 50cm off the floor
Take pulse for 1 min and record in a table
Step on to the bench and off again for two minutes. A step up and down should be as followed:
- Step up with on foot
- Step up with the other to stand straight
- Step down with the leading foot
- Step down with the other to the original starting position
Take pulse for 1 minute and compare with original
Diagram
Results
Graph
Conclusion
From the graph you can see that my prediction was correct in the fact that the heart rate does increase as the body exercises.
As the body exercises the muscle cells in your body need more oxygen so that they are able to work for longer and quicker. To supply the cells with more oxygen requires more blood to be pumped around the body and at a faster rate, as it is the blood that is the carrier of the oxygen. The blood needed to be pumped faster so the heart was forced to pump more frequently per minute and it is this that causes the heart rate to increase.
Evaluation
I worked well during this investigation. My prediction came to be proved correct and I have shown that exercise affects the body.
However, if I were to do this experiment again, I would make the following two changes:
- Conditions: I would do the experiment in a controlled environment where the conditions could not change so that I knew for sure that there was no way that my investigation could differ each time.
- Equipment: I would use a heart rate monitor as used in hospitals so that I could get more accurate results than by just determining my own pulse by using my hands to find my pulse.
The problem with doing the experiment in classroom environment is that there are many ways in which the experiment can be tampered with so that it is not accurate. Ideally all experiments would be done in controlled conditions using computers that can be programmed to do the same things exactly the same over and over again.
