I yawned one time while reading this thread. True story.
Eh, I always had troubles inhaling as much as I knew my lungs could hold. Through some sort of minor miracle, not that I'm not grateful, meditation actually fixed it. I think it was muscle tension - I went to bed that night and my ribcage just fell down towards my spine, empty of air. Very comfortable, until I had to breath :P
I'd say just lay on your back and exhale. See how much you can empty your lungs - if it feels like you have to force the air out to make the ribcage 'collapse', then yes you are probably tense one way or another.
I was going to post about this myself (still may, if I don't get what I need from answers). I'm fifty, just starting out PBF, have been easing into everything and making really good slow progress over the last month.
But when I started doing the Novice Sprinting, I found I can't breathe deeply enough when I'm slightly winded (at 75% effort). I breathe from my belly, I recover pretty quickly, within 30 seconds, and am breathing slowly and normally within a minute or two for my next go. And it seems to have improved the second time around. But it was very disconcerting.
I've never smoked, have no history of lung problems or breathing problems. So we'll see if it continues to improve as I condition myself. But if anyone has any other suggestions, they are welcome. (I'll try the paper bag thing, too.)
GroketteInND - If you're not used to working out at that level of exertion, your body may have an anxiety response to working that hard. It's like a very mild anxiety attack, and that may cause you to feel like you can't breathe deeply enough. It should improve as your body gets used to working hard.
Thanks! I figure that's what it is, it is getting better. So I'll just keep pushing a bit more every time.
I don't feel anxious, though, I feel really good!
I've experienced this exact problem since I first got into sports at age 14. At first my parents took me to the doctor and I was given an asthma inhaler, but it had no effect. It's definitely not asthma. It's more like, I try to take in a full breath, and that last sip of air that would make it full just won't happen, no matter how hard I try.
Over the years, I've just gotten used to it. No amount of exercise or conditioning changes it. I find it's worse on certain days and nonexistent on others. I've never been able to figure out what causes it, but after a lot of trial, error, and self-experimentation, I've narrowed down that it's somehow related to muscle tension in my diaphragm and ribs.