Which factor will decrease in response to increased cardio respiratory fitness

working in the cardio will help to tone your abs and burn excess fat, and the respiratory system, with it being in good health from the exercise, your oxygen intake and the release of carbon monoxide will definitely increase and become steadier..

What are the items? ?

If this is a multiple choice give me the choices ! but id say  he always states the truth. unless its not a choice lol.-hope this : 3