Build your own stethoscope and try different ways to measure how your family's heart rates change with exercise!
18 in. of vinyl tubing (from a hardware store)
1 empty plastic water or soda bottle
stopwatch or clock with a second hand
paper and pencil
Measure your resting heart rate with the pulse method first by placing an index and middle finger on the inside of your wrist, beneath the palm of your hand, and pressing down firmly. Count the number of beats for 10 seconds and multiply this by 6 to get the number of beats per minute (bpm) and record. For better results, sit quietly for a few minutes before taking your measurement.
Together, make a stethoscope by cutting off the bottom third of a water or soda bottle and inserting the vinyl tubing into the mouth of the bottle. Secure it with duct tape. Place the stethoscope on your chest and move it around to find the spot where the heart beats the loudest. Take turns listening and recording each family member’s resting heart rate.
How do the resting heart rates from these two methods compare? If you are physically able, try running in place for 1 min. and check your heart rate again. What happens?