When you’re having sex, breathing is the last thing on your mind. But breathing sets your tempo, and in bed good rhythm is a LOT better than bad rhythm. Coach Kendra explains how it works and further provides breathing exercises that helps you control the rhythm during sex.
Hip to be... 
I read that lack of proper breathing or holding your breathe during sex comes from a habit developed when masturbating. As a kid, most people masturbate in the bathroom or in the bed where they’re sibling my be sleeping. Therefore, the person tries to be as quite as possible and holding their breath starts to develop. It’s a habit that stems from the secrecy of jerkin’ off. I recommend to practice breathing deeply the next time you are masturbating by yourself until it becomes natural to breath again during pleasureable activities.
Funny how I actually moan a lot during masturbation….but that’s just me LOL