The hypothesis is that people with a higher body mass index who do not exercise regularly will have a higher pulse because of the higher strain on their heart.

You will measure the height and weight of 10 boys and 10 girls, calculate their BMI, and divide them into categories for exercisers and non-exercisers. Then, measure their pulse rate before and after doing jumping jacks and walking up and down a staircase.

You will need 10 boys and 10 girls between the ages of 11 and 13, a BMI chart, and a way to measure pulse rate.

The results of this experiment showed that the hypothesis was incorrect. As BMI increased, the pulse rate decreased. This is probably because pulse has more to do with weight than how often a person exercises. An interesting fact was that the change in pulse was higher with the stepping exercise than it was with the jumping jacks.

This science project is interesting because it shows how body mass index affects the cardiovascular system in a surprising way.

Variations to consider include using more people with higher BMI's to get more accurate results, or measuring the pulse rate of the participants before and after running instead of jumping jacks and walking.