Science Buddies: "Ask an Expert"

For my project I have to test my heart rate with different types of exercise.For my project would it be ok if I tested three people?If I was able to test three people what would be a good amount of trials to have a reasonable result?

Hi,

Three subjects would be the minimum number to test--five would be better. There are a lot of variables that you need to consider in choosing a subject. How old are they? Do they exercise or play sports regularly? Are they male or female? Is their weight (BMI) in the normal range? As to the number of trials, scientists usually do at least three, but the more trials you do the more accurate your results.

What kind of exercise are your subjects going to do? Are you using a wearable device to measure beats per minute? When you repeat a trial, make sure the subject's heart rate has returned to baseline before doing the test again. There is another important test you could do and that is to measure the time it takes for the heart rate to return to normal after exercise is stopped. Athletes or those who do cardio workouts will have heart rates that return to normal more quickly than a person who doesn't exercise much. This time is called the heart recovery rate: http://www.livestrong.com/article/44897 ... n-to-base/

Any more questions? Just ask away...

Sybee