Cardiovascular System Science: Investigating Heart Rate Recovery Time

• Pen or pencil
• Scrap piece of paper
• Clock or stopwatch that shows seconds
• Simple and fun exercise equipment, such as jump rope, hula-hoop, stepping stool, etc. Alternatively, you can do exercise that does not require equipment, such as jogging.
• A chair
• Calculator

1. Practice finding your pulse. You can do this by using the first two fingers on one hand to feel the radial pulse on the opposite hand’s wrist. The radial pulse is found on the “thumb side” of the wrist, just below the hand. You will need to be able to find your pulse quickly, so practice finding it until it is easy to do. 
2. You can alternatively use your carotid pulse, but make sure you know how to take it safely by pressing on your neck only very lightly.
3. Prepare a scrap piece of paper so that you can quickly write down your testing results when doing the activity. You will be measuring your resting heart rate, your heart rate immediately after doing a short exercise, and then every minute for the next five minutes. After that, you will measure your heart rate every two minutes. You will continue to measure your heart rate until it returns to your resting heart rate.

1. Measure your resting heart rate. To do this, take your pulse (when you have been resting) and multiply the number of beats you count in ten seconds by six. This will give you your resting heart rate in beats per minute (bpm). What is your resting heart rate? Write it down on your prepared scrap piece of paper.
2. Choose a vigorous activity you’d like to briefly do. This could be jumping rope, stepping on and off a low stool, hula-hooping, jogging, etc. Then, engage in that activity for about two minutes.
3. Immediately after the end of the exercise period, sit and rest on the chair and quickly measure and record your heart rate. What is your heart right after exercising? Write down what time it is (including seconds) or start a stopwatch.
4. While you continue to sit and rest, measure and write down your heart rate every minute for the next five minutes. How does your heart rate change as you continue to rest after you stopped exercising?
5. If your heart rate has not reached your resting heart rate, continue to sit and rest but only measure and write down your heart rate every two minutes. Continue measuring it until it returns to your resting heart rate. How does your heart rate continue to change over time?
6. What was your heart rate recovery time, or the amount of time it takes your heart to return to its resting heart rate after exercising? How did your heart rate change over time after you stopped exercising? 

Extra: Graph your results. How did your heart rate change over the course of this activity?

Extra: Try repeating this activity but compare a group of athletes to a group of non-athletes. How does the heart rate recovery time of people who are physically fit compare to people who do not regularly exercise? 

Extra: Do this activity again but this time include volunteers of different ages. Does heart rate recovery time increase with age? Be sure that the volunteers you recruit can safely do the exercise!

Extra: Design an activity to compare the heart rate recovery time of people who smoke to people who don’t. Do smokers have increased heart rate recovery times compared to non-smokers?