How Do You Know if You're Breathing Inefficiently?

Met interrupted a train of thought. How do people not know that? This has always befuddled me, because i've been running beside somebody in a marathon or tro race n im. I don't understand how that even happens. Like, i can't even give him the counsel to course correct. It's so befuddling to me. And some people are new to the sport and don't know what's normal. They haven't spent enough time around other athletes to know that they're doing it wrong. Sometimes people just get into a rhythm and get into a habit. You see an older person doing it in the fifties or sixties,. maybe they've been breathing