The stages of breath holding in the body without prior hyperventilation

[Conan777]

Let's say that in a swimming pool during the summer, a kid goes underwater decides to hold his breath past the urge to breathe that usually gets people to go back to the surface for air. When that kid can hold his/her breath for 45 seconds before the burning urge to breathe, what would happen to his body, in stages, when he/she willfully resists the burning urge to breathe and tries to hold his/her breath for something like 7 minutes long. I know that if that kid wee to hols his breath like way past 45 seconds, he/she would get strong chest contractions, which is the intensified burning urge to breathe.

 

[Kiekerjan]

In the scenario you described the kid seems unexperienced (going from 45 seconds to 7 minutes? good luck!), since he doesn't really know what to do the phases would probably look something like this:
1. waiting
2. contractions
3. "this sucks why the hell am I doing this"
4. gives up

For a trained apneist it would look very different. The first phase would start already when he's still breathing during which he relaxes his body and mind and through controlled breathing he prepares himself for the hold. After taking the big breath the second phase begins during which the entire focus is on relaxation. During this phase he might do body scans to find tension and relieve it. He clears his mind from any thoughts and expectations or might apply some visualization techniques. This part is full on meditation! The third phase starts when the contractions hit, they'll come slow and irregular at first. He tries to maintain his relaxation and allow the contractions to come without resistance. Eventually the contractions become stronger and start to create a rythm. They keep coming faster and stronger until it becomes a real fight, this is where the apneist needs a very strong determination because the mind will come up with any excuse to make you stop. When the breathhold is over he pulls his head out of the water but he knows he's not done yet, this is when the final and most important phase starts: recovery breaths!

 

[Conan777]

In the scenario you described the kid seems unexperienced (going from 45 seconds to 7 minutes? good luck!), since he doesn't really know what to do the phases would probably look something like this:
1. waiting
2. contractions
3. "this sucks why the hell am I doing this"
4. gives up

For a trained apneist it would look very different. The first phase would start already when he's still breathing during which he relaxes his body and mind and through controlled breathing he prepares himself for the hold. After taking the big breath the second phase begins during which the entire focus is on relaxation. During this phase he might do body scans to find tension and relieve it. He clears his mind from any thoughts and expectations or might apply some visualization techniques. This part is full on meditation! The third phase starts when the contractions hit, they'll come slow and irregular at first. He tries to maintain his relaxation and allow the contractions to come without resistance. Eventually the contractions become stronger and start to create a rythm. They keep coming faster and stronger until it becomes a real fight, this is where the apneist needs a very strong determination because the mind will come up with any excuse to make you stop. When the breathhold is over he pulls his head out of the water but he knows he's not done yet, this is when the final and most important phase starts: recovery breaths!

I am not asking about an inexperienced person. asking about what would happen to the body, scientifically, of a determined swimmer if he/she tries to hold his/her breath way past his/her time that the burning urge to breathe starts on the breathhold. Lets say that a determined, strong swimmer at a swimming pool tries to hold his/her breath as long as he/she wants WITHOUT prior hyperventilation. If that swimmer tries to hold his/her breath past 45 seconds to like 7 minutes, like I said earlier, I am asking what would happen to his or her body? Would the contractions get stronger? What would be the end result? This article, http://www.artofmanliness.com/2015/08/17/how-to-hold-your-breath/, kind of shown me the stages of what would happen to a free-diver if he tries to hold his/her breath way past his/her time when the burning urge starts. But in a swimming pool, I'm not really sure because a recreational or a competitive swimming pool has very little pressure change compared to how deep the freediver goes, like 60ft, even hundreds of feet deep. So I don't think a spleen squeeze can happen in a recreational or competitive swimming pool. If a determined swimmer in a competitive or recreational swimming pool that is usually at most 6 feet deep, that tries to hold his/her breath way past the urge to breathe like for 10 minutes, when the burning urge to breathe starts at 45 seconds, would his/her body go through the stages like the article described.

 

[Kiekerjan]

In that case it's a little more complicated than simply a succession of phases.

The spleen effect is part of the mammalian dive reflex which can be triggered in different ways: by exposure to water on the face, by pressure, and by holding your breath. Of course a freediver is exposed to all 3 so the effect triggers very fast. However, it is also possible to trigger the effect simply by holding the breath. The mammalian dive reflex is not related to a specific phase of the breath hold, it's more like a mechanism that once it's activated will remain activated for the duration of the dive session. This is one of the reasons freedivers do warmups, because with the dive reflex activated it becomes much easier to hold your breath. Other physiological changes that occur with this dive reflex are a slower heart rate, peripheral vasoconstriction (restriction of blood flow to the arms and legs to preserve oxygen for the vital organs), and blood shift (blood collecting around the lungs to protect them from collapsing from the pressure)

If we're just talking about a single breath hold, the dive reflex might at some point kick in but it would be impossible to tell in advance during which phase of the breath hold. There's a good chance that it won't do so at all until the second or maybe even third consecutive breath-hold attempt.

You could see the breath-hold as having the stages that I mentioned in my previous post, and then the mammalian dive reflex happening simultaneously, but unrelated to the phases. For example it is possible to activate the dive reflex before your maximum attempt breath hold and have all the mentioned benefits from the start before you have any contractions. Or alternatively, it would be possible to perform an entire breath hold without the dive reflex being activated at all.

Hope this clears it up a bit

 

[SubSub]

Could they restrain themselves from going up, they would most likely drown. A apneaist does a mental exercise to relax his body, lower heart rate, minimize co2 consumtion. A "normal person" would most likely start to panic, build up adrenaline and consume co2 like never before = drown pretty quickly. My layman thesis.