This type of exercise is what strengthens your heart and lungs, burns a ton of calories and fat, gives you energy to make it throughout your day, and reduces your stress level. Anaerobic exercise doesn't require a certain level of oxygen to be maintained. For example, weight lifting doesn't require an increased level of oxygen to perform a lift. A weight lifter certainly increases his rate of breathing during a heavy lift, but maintaining an increase in that oxygen level is not necessary for gains in muscle strength or size to occur.
Oxygen is in abundance during aerobic exercise.
Exercise is considered aerobic when you are taking in enough oxygen for fat metabolism to occur. The main reason we exercise is to burn fat, because it is our primary fuel, therefore we want aerobic exercise to be the center of our fitness programs. Just because you are taking in a high level of oxygen doesn't mean you should go as fast and as hard as you can to burn the most fat. It is very possible to work TOO HARD , and turn your aerobic exercise into anaerobic exercise. Simply put, you stop burning fat, and burn only sugar.