To examine the link between the rate of respiration and the amount of exercise done by exercising vigorously and recording pulse rate.

Glucose     +     oxygen     --      Carbon Dioxide     +     Water     +     Energy

The chemical formula is:

C   H   O     6O        --      6H   O     +     6CO

This reaction happens in every cell in the body. During exercise you burn more energy than when resting so you breathe faster and harder to get more oxygen into your body where it is then pumped round in your bloodstream and it goes to every cell in the body. In order to cope with the extyra oxygen your heart beats faster in order to get the blood round the body to the cells. This means that you pulse rate increases, to measure this increase the pulse can be taken before and after exercise.

Method:

1. Take the subjects pulse rate for 15 seconds and multiply it by four in order to get the subjects pulse rate in bpm (beats per minute). This is then recorded.
2. The subject then does steps for 30 seconds.
3. The subject stops and pulse rate is measured and recorded.
4. The subject then relaxes for 2 minutes and their pulse rate is checked once again to see that it is back to normal.
5. When their pulse has returned to normal you then repeat steps 1, 2, 3 and 4.
6. Once you have done three sets of steps for 30 seconds, you then move the time up to one minute and repeat steps 1, 2, 3, 4 and 5 again. Increase the length of exercise by 30 seconds each time until 2 minutes 30 seconds

Equipment:         Stop watch

                Stairs/a step.

        `        Someone to measure the subjects pulse.

Fair test: To ensure that this is a fair test, everything will be kept constant aside from the variable which will be the length of time that the subject exercises for.

Prediction: I predict that the more exercise the subject does, the faster their pulse rate will become but if they exercise for an extended length of time their pulse rate will stop increasing and maybe decrease a few beats as the person settles into the exercise.

Table of results:

Graphs:

Analysis: By looking at my analysis I have seen that my prediction was right. You will see that the subjects average heart rate goes higher in the shorter periods of exercise and in the longer periods of exercise the subjects heart rate increases but then appears to reach a peak and then decreases slightly as it settles.

Evaluation: I think the experiment went without any major problems. My method worked although I think we should of used a metronome in order to make sure the subject did the same exercise in all of the attempts because they may have done the step-ups slower or faster at some points which would of effected their pulse rate. This could be why the average pulse rate drops slightly in the last go. I think I could of changed the way we went about things by instead of timing the amount of exercise we did we could of done it so that we counted it by how many step-ups the subject did like 30 step-ups, 50 step-ups, 70 step-ups etc.