Provide benefits for the heart and lungs.
•Oxygen from the air we breathe must be delivered to the muscle cell deep in the body and enter the mitochondria to be used.
•Production of large amounts of energy in the form of ATP.
•This process may be enough to handle mild and moderate levels of exercise but may not be able to meet the demand of very strenuous (hard) exercise.
•This system is used primarily in sports emphasizing endurance, such as distance running.