Resting heart beat and oxygen intake

How do you decrease your resting heart rate? And how do you increase your oxygen intake while breathing?

Exercise helps get your resting heart rate down. Cardio more so than weights but both work. VO2 max is mostly a cario conditioning thing. The more you work your heart and lungs the more efficient they get, to a point.

I have a low resting pulse, right now it’s 64. When I’ve been working out more often it’s usually 44-48.