By saturating your body with oxygen you are giving it what it needs to operate at it's maximum potential. We are each born with billions of brain cells, and when we deprive them of oxygen, they will react as if starving and will not give you the performance they are capable of giving. Both active and passive aerobic breathing involves deeper breaths but those deeper breaths need to be primarily effortless. With effort you have an oxygen cost of breathing that negates many benefits and can actually create breathing blocks. . This allows the oxygen to saturate the blood stream and circulate to feed every cell in your body, muscles, brain, organs, skin, and at the same time is allowing your metabolism to speed up to burn fat and tone your muscles.
Most people only use about twenty percent of their lung capacity.
My theory is that we have been programmed to believe that nothing as simple and easy as breathing could possibly make that much of a difference. Because of my training and experience it is the most logical thing I can think of. In simple terms, aerobic means to get enough oxygen into the bloodstream to convert to fuel to burn fat. We have again been programmed to believe that aerobic means running around a room and jumping up and down. What most people don't realize is that people who do this type of exercise have to do it consistently for about 20 minutes to put the body into an aerobic state.