heart and lungs travel

Have students travel “through” the heart and lungs by participating in this instant activity.  Students are to pick up a piece of oxygen (yellow ball) and take it with them as thye travel through the course.  At the end of thier travel, one lap around course, they are to drop off their oxygen and pick up one other piece of oxygen (yellow ball).  The more balls you use, the more trips the students have to take throughout the course.  They really enjoy this activity and it reindforces the concept of oxygen use during exercise.  Good luck!  Tom