What you're looking at is a balanced equation of sucrose (food) plus oxygen (breath) producing carbon dioxide (exhale) and water (sweat). Exactly 10 grams of sucrose is converted to the right (lower) side via the oxygen in about 70 breaths.
I was doing chemistry conversions, balancing reactions, and this simple truth popped up in the depth of complex systems. And it really is this simple. You breath. And you use up energy.
I've heard people talk about being "bad" at breathing in workouts. That's a problem. Because, quite literally, all you need to do to improve body composition and athleticism is breathe. People will join the latest trendy fitness boutique and buy every supplement known to man before they even consider improving their breathing skill and practice. Talk about cart before horse. I've had clients look at me like I'm insane when I repeatedly talk about the central importance of breath skill. It won't just take care of itself. You have to put intent into it.
Day 1, I have every client or student do intentional breathing and 100% want to skip this "step." It's not a step. It IS everything. The chemistry CANNOT be done for anything in fitness without increasingly adding oxygen to the system. For those who hear me, they get 5-10% jumps in performance right away.
By no means am I an advanced meditator; but even I can totally alter my emotional and physical state via my rudimentary breathing practice. Plenty of my stronger or more conditioned buddies have slower rowing sprint times than I do, simply because I have learned to calm myself in an all-out sprint. My wife has seen me drop my heart rate into the 20s bpm just by focusing on breath. One of my buddies recently watched me drop my standing heart rate (after having caffeine and working out) from over 100bpm to around 60bpm in less than a minute. And none of this is even advanced.
Wim Hof is advanced. Tibetan monks are advanced. You? Just practice.