Personal anecdote: I do freediving, so CO2 tolerance training is common, and I've done it on and off. Basically you do breath holds to train your body to get used to high leves of CO2.

I've found that brief high C02 levels are very good for activation, and to get out of a lethargic state. I don't know if a mix of cortisol and vasoconstriction and dive reflex triggered by the CO2, but I feel like it's a tool I have on my toolbox whenever I need to so something difficult or that requires a lot of will power.

It's not for everyone tho, because many people can't get past the initial urge to breathe, and would probably freak out with the first involuntary contraction.

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Azrael3000 8 months ago | parent | next [-]

I also tend to use my freediving experience for the opposite, when I'm highly stressed I tend to do one or two short (full exhale) breath holds to calm down. This works amazingly quickly and let's me refocus. Note, this will probably not work for untrained individuals.

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gosub100 8 months ago | parent | prev | next [-]

I'm in a bad spot because I love swimming but I can barely hold my breath for 20s.

	▲	abandonliberty 8 months ago \| parent [-]
		As were many of us before our first introductory freedive course.

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FollowingTheDao 8 months ago | parent | prev [-]

Is it healthy to get into a near death experience just to get something done?

Why is it "bad" to be in a lethargic state?

Have you ever asked yourself these questions?

	▲	jboggan 8 months ago \| parent \| next [-]
		I wouldn't characterize it as a near death experience but an activation of the mammalian dive reflex. It's a pretty profound physiological set of changes that most people have never experienced, oddly.
	▲	samus 8 months ago \| parent \| prev \| next [-]
		You don't get near death experiences just by holding breath, not even close. You might eventually be able to make yourself pass out though, so never ever practice long breath hold under circumstances where a loss of consciousness would be a danger, e.g., while driving, close or in water, close to streets or high drops or stairs, etc. Lethargic states stop you from doing what you want to do and to manage your time effectively. Allocate time being in such states for resting or sleeping hours.
	▲	elric 8 months ago \| parent \| prev [-]
		What makes you say that breath holding for diving is a "near death experience"? It's pretty safe from what I can see?