The way it works is you do cardio and burn fat right, When your body burns a certain level of fat it sais i need this much fat in order to operate correctly, so it stores it, it starts to scale out your muscle and fat percentage in order to be proficient, it sais i dont need this much muscle mass it's just causing me to expend to much energy in order to operate, your body is like a machine, It will actually burn the muscle becuz it thinks the fat is more eccential, sucks dont it.
What i meant By your oxygen intake level was once explained to me by a pro, wish i could remember the way he explained it i thought about it i cant explain it the way it was explained to me and dont want to give out bullsh*t info, all i know is it has somthing to do with your heartrate and oxygen intake level..owell hope i cleared up some confusion on that first issue.......PEACE