During aerobic exercise, you breathe faster and deeper than when your heart rate is at rest. You're maximizing the amount of oxygen in the blood. Your heart rate goes up, increasing blood flow to the muscles and back to the lungs. During anaerobic exercise, your body requires immediate energy.
Aerobic exercise stimulates the heart rate and breathing rate to increase in a way that can be sustained for the exercise session. In contrast, anaerobic without oxygen exercise is activity that causes you to be quickly out of breath, like sprinting or lifting a heavy weight.
