Respiration:
Glucose + Oxygen ───> Water + Carbon dioxide + energy
C H 0 + 6O ────> 6H O + 6CO
Controlling variables
- I will measure my heart rate.
- I will vary the length of time of one exercise.
- I will measure my resting heart rate as a baseline measurement.
EQUIPMENT
Preliminary investigation
RESULTS
Resting rate: 70
Prediction
I predict that as I increase the timing of doing the exercise, my heart rate would also increase. I know this because I can see this from my scientific theory and from my preliminary results.
FAIR TEST
- Counting the heart rate after doing the exercise for a certain period of time. E.g. 1 minute.
- Doing the same exercise.
- Doing the exercise at the same environment.
- Measuring the time accurately using the stop watch.
- Taking the pulse rate from the same pulse point at all time. E.g. wrist.
SAFETY
- Tie your hair back (girls).
- Keep the place clear where you do the exercise.
Method
- I first took my normal pulse rate for 1 minute.
- Then as soon as I started the stop watch, I started to jog on the spot for 10 seconds.
- I took my pulse rate again for 1 minute after I finished jogging on the spot for 30 seconds.
- I continued doing the same exercise by increasing the timing, by 30 seconds each time, until I got enough evidence.
- And while doing the exercise I made sure that I had some rest between each exercise until the heart rate became normal before starting to do the exercise again.
- To make it a fair test, I repeated everything again and took the pulse rate.
- Finally I recorded my results on a table.
RESULTS
Resting rate: 70
Conclusion
From the results I got I am able to work out that my prediction was absolutely right because I predicted that my heart rate would go up as I increase the timing of doing the exercise. I can also see from my graph that my heart rate kept increasing each time and not decrease. As soon as I began to do the exercise, the rate of respiration in my muscles increased and more carbon dioxide was released into my blood. And that is the reason why I started to breathe faster. When the level of carbon dioxide in the blood raised and as I started to breathe faster, my heart rate slowly increased automatically. My results did not double up when I increased the time of doing the exercise. And I think this is because our pulse rate can only increase for a certain amount and if I continued to do the exercise, I would then start to produce lactic acids and my muscles would go stiff, and if I continued to do the exercise even after that then I might fall down because of the less amount of energy in my muscles.
EVALUATION
My investigation was relatively interesting and it went quite well. As I predicted I got quite interesting results and even though different people got different pulse rates, in the end we all got the same kind of graph. I.e. when the timing of the exercise was increased, the pulse rate increased too. I think I collected enough evidence to get a reasonable graph. And when I repeated my practical (to make it a fair test) I got almost the same results, only a small difference. And that is why I decided to take an average result.
I can also say that I did not get any strange results and I can say this by looking at my graph. If I had more time to do this experiment, then I would have done it in two different conditions (e.g. morning and evening) to see if there was any difference in heart rate due to the different conditions. To make my conclusion more certain, I would also try to do a range of different exercises and compare to see if there was any affect in doing different exercises.
I did my practical twice to get more accurate and reliable results. But if I repeat this experiment again then I would try to get a big range of different results. But this time I will use a “heart rate monitor” to make it more accurate and reliable. I can’t exactly say that my results now are accurate because there are chances of human errors like for example I might have made a mistake while counting my pulse rate (loosing the counting).
