The Power of Our Lungs


Students become aware of how much air they must breathe each day to survive, the importance of lung capacity to daily activities, and the value of clean air.


  • 9 Inch round balloons for each student
  • Small plastic bags
  • String cut into equal lengths to seal off balloons


  1. Inform the students that everyone will have the opportunity to blow up a balloon, but that to streamline the experiment there will be two groups taking turns.
  2. Divide the students into two lines facing each other. Give each student in one line a piece of string and give the students in the other line a balloon.
  3. Instruct the balloon group to stretch the balloon, take a practice blow into the balloon, and then let the air out of their balloons. Then tell the students to take one deep breath, blow into the balloon for as long as possible, and quickly twist the neck of the balloon so air does not escape.
  4. The student with the string should then quickly tie a tight knot around the twisted neck. Each student should keep the balloon he or she blew up. Exchange groups, and repeat the process, so that all students have an inflated balloon.
  5. Compare the sizes of balloons among the students. Wrap a piece of string around a balloon at its widest part to measure circumference of the balloon. Then hold it up to a yardstick. Record the distance around the balloon to the nearest 1/8 inch. Compare the relative lung capacities of the students by making a chart or graph.
  6. Ask students how many breaths they will take in their lifetimes. Have them count the number of breaths they take in a minute and record it. To estimate the number of breaths in a lifetime, multiply breaths per minute by 60 minutes, times 24 hours, times 365 days, times 75 years.
  7. Have students estimate how much additional oxygen they need as they exercise, by comparing the number of breaths per minute after doing jumping jacks for 30 seconds or a minute with their "resting" number of breaths. Or try running for a minute to see how that affects your breath.
  8. Interesting Fact: If you could spread out your lungs completely flat they would be equal to the size (surface area) of a tennis court. That large area allows adequate oxygen exchange with the blood; smoking and/or breathing polluted air reduces the lungs' effective surface size.
  9. Adults breathe 35 pounds of air every day. Have students lift something that weighs approximately 35 pounds to get an idea of the exact weight.