The most convincing explanation that I heard was that by building up a tolerance in your body to carbon dioxide, you actually train your body to oxygenate itself better. CO2 dilates blood vessels and helps transport oxygen where it needs to go so it's not just a waste product.

When you're short on breath, the feeling is not actually due to a lack of oxygen but due to an excess of carbon dioxide. This is why just by starting to exhale after holding your breath, you immediately feel better, despite not having inhaled any additional oxygen. By holding your breath all the time you teach yourself to tolerate more CO2.

For some weeks I'd practice holding my breath all the time say while I'm driving or working, holding on each breath (maybe 20-30 seconds until my diaphragm starts to try to breathe involuntarily), maybe an hour at a time or more, but I find you need at least 20 minutes or so to feel an effect that lasts longer than a few minutes. You do get to a point where you really feel different throughout the whole day and your breathing slows down naturally.

I don't see why science is so resistant to researching disciplines involving the breath. Breathing is literally your most important source of energy, common sense would tell you there is something there to unpack.

I've deeply wondered about the question regarding why science and modern medicine have largely ignored breath as a topic of health. Part of the explanation I believe is that it doesn't make anyone any money. But, this can't be the total explanation. It's frankly astonishing. Studying someone's breathing habits should be part of routine medical exams and general wellness check ups. No M.D. that I have ever been to has ever brought it up, and when I've asked them about it, they shrug and give me a weird look, as if I'd asked them about UFO sightings. It's phenomenally strange.

Slow breathing, unless you are doing it to an extreme, doesn't actually significantly alter blood oxygen levels. Mostly you are dealing with carbon dioxide levels. In fact, due to the dilation of the blood vessels caused by CO2, cellular oxygen levels can go up when breathing slows down, as more blood is delivered to the cells themselves. It takes quite a lot of stress for O2 to drop for normal people who haven't pre-trained themselves into getting comfortable with raised CO2, quite longer than any sort of remotely comfortable breathing technique. In other words, the urge to breathe is actually generated by increasing CO2, not falling O2. If you put yourself in a chamber with normal CO2 and abnormally low O2, you wouldn't feel an urge to breathe faster, you'd just eventually become delirious. So the analogy of caloric restriction to O2 restriction isn't actually applicable for gentle, even mildly uncomfortable, breathwork. But it's still an interesting idea.

Oxidative stress can be reduced by eating foods that produce less metabolic waste, e.g less unstable polyunsaturated fats and getting all the necessary nutrients that are protective against the damaging effects, e.g vitamin E.

If you just eat less, make less energy, do less, you get net neutral state of a longer life lived more slowly. Not worth it in my estimation.

"If you just eat less, make less energy, do less" I would wager the modern reality is that people do less as they eat more, not the opposite. The people on extended caloric restricted diets I would wager to be far more active.

Yes and that's the problem, you have people who eat too little and do too much that end up with stress related illnesses and people who eat too much and do too little who end up with obesity related diseases.

Ideally you want to maximize your metabolic throughput while keeping it as clean as possible and have an active life to use the calories.

Eating enough clean food is definetely the best, yeah. Even for losing weight I don't think eating a extremelly calorically restrictive diet is the way to go unless you are in immediate medical danger. Just didnt agree with the idea that people who really eat whatever they want in whatever quantity they want generally lead a very active lifestyle.

I’ve never understood how extended caloric restricted diets are supposed to work without continuously losing weight. I understand that if you eat under maintenance you may lose weight and have a lower maintenance level and stop losing weight but then doesn’t it stop counting as calorie restriction?

I've never done it, but I believe your body will adjust its metabolism to match your calories, eventually. Otherwise, you would continuously lose fat and muscle until you die, so yeah you can't eat under what you're body is using forever.

aging triggered by oxidative stress and limiting oxygen to limit metabolic waste are both very interesting thoughts. thanks for sharing.

can you share some of the reasons you remain skeptical on the health benefits of slow breathing? if you had $1m to fund an experiment to prove/disprove your hypothesis on breathing, how would you design the experiment?