So, what happens when the wind gets knocked out of you is that all the air in your lungs is forcibly ejected from your body. (Literally, the wind gets knocked out of you.) The only way to recover from that is to get the wind back into your body, and that is all posture.
When we’re winded, our first instinct is often to lean over. You’re breathing heavily, your back gets tired, and you just hang there. (Basically what happens when you get punched in the gut, except the gut punch is the more severe version.) This is one of those bad instincts because it keeps you from getting that air.
You’ve got to get yourself upright and breathing, get the oxygen back into your lungs. The oxygen goes from your lungs to your blood to your tired muscles including your new injuries in the abdominal muscles and that’s what helps you recover.
You’ve got to straighten, open your chest, and force yourself to take long, deep, controlled breaths with your diaphragm. Your body won’t want to do that. It’s gonna hurt. Your body is going to want to stay bowled over. However, when you’re hanging there your ability to breathe is negligible. You won’t get enough air into your lungs for it to matter. Unless you’re doing a sport or practicing martial arts they’re not going to tell you how important breathing is.
One of the first things they will teach you in any martial art is how to breathe. Most people breathe using either their lungs or their stomach, you don’t do either. You breathe with your diaphragm. The faster you get air back into your body then the faster you recover. (This works in the short term too, the more oxygen you get into your lungs then the faster that gets to your muscles which helps them recover. If you cannot breathe then you cannot fight for long periods, or perform any sport. That hissing sound you often hear in martial arts movies that lots of people make fun of? That’s them breathing. The kihap is also breathing. They’ve trained their bodies to exhale on the strike, which negates the chance of having the wind knocked out of you when you’re hit in the stomach.) The more we work out and practice at this then the stronger our lungs get and the better we become at breathing.
Breathing is a learned skill.
The best part about rigorous physical exercise is that you’re used to being out of breath so you learn to work through it, recover faster, and get back in the game. Practice is how you get your breath back.
Basically, you had to straighten in order to smack your back which is what let you recover your breath.