mammalian dive reflex short history

    I gotta admit, Myth number one is more like happens to me. I've been laying on the bottom and although I haven't actually monitored my heart rate, I'm sure that it isn't slow. And I think to myself, "damn, I thought it was supposed to slow down....what am I doing wrong here"?

    That site about the reflex being a myth complete and utter BULLSHIT. There are NUMEROUS peer-reviewed papers on this very subject!


    Here's one of many!
    Mechanism of the human diving response


    It happens as soon as COLD water touches the face. The reflex is primarily triggered in COLD water. As soon as this happens, your heart rate slows down, the blood vessels in your extremities start constricting to send more blood to your vital organs and if you dive deep enough, your organs will allow plasma and water to pass into the thoracic cavity to keep pressure constant.


    When I worked in the ER. Some doctors that I worked with even tried it for treating SVT. It's a real thing folks.


    I dont think that article disagrees with those conclusions. it even says at the end.


    "If you still think the Aquatic ape theory is true because heart rate drops on face immersion in cold water. Dream on - Heart rate slows down because of the temperature change, not the water."


    Basically it seems to me to be saying that while there are very well known physiological responses triggered during freediving they have nothing to do with some innate diving ability given to us by aquatic ancestors and evolution, but instead extraneous factors such as colder temperatures, pressure, stress, lack of oxygen etc. I dont think it denies that things happen in our body as we dive that allow us to hold our breath longer, but more that these responses are your body trying not to die, rather than some romantic "dive response" or "aquaticity" evolved into us we haven't tapped till we go diving.



    Also lots of TED things are bullshit. They will give anyone who can entertain a crowd, sell tickets and get youtube views a platform for their "science". They do review them but only to the standards of "seems legit and sounds interesting". And the TEDx talks are even worse as there is no oversight at all.


    Thats not to say this TED talk is bad. But if anything TED talks are something to be skeptical towards rather than trust as an authoritative argument.

    Edited 8 times, last by Reefchief ().

    The increase in heart rate and blood pressure makes sense to me.


    It mentions blood flowing from the extremities to the core organs and this is documented in seals. But their extremities are a small part of their total mass compared to us.


    If the veins and arteries in our arms and legs become restricted, it seems logical that the only thing that could happen is pressure increased in the whole circulatory system. And to compensate for the decrease in 'pipe size" (hey, I"m a hatchery operator:D) and maintain the flow rate, you have to increase the pump capacity, which in this case means the heart would have to pump faster.


    Just thinking out loud here….this stuff is fascinating.

    The occurrence is called shunting. It is real. We are aerobic animals. All of our cells require 02 but we have built in priority lists. This is part of the danger of swb. Our lungs expand and draw o2 to them even if out body had made the decision to divert it elsewhere

    i like to spear fish

    Quote from Reefchief

    I dont think that article disagrees with those conclusions. it even says at the end.


    "If you still think the Aquatic ape theory is true because heart rate drops on face immersion in cold water. Dream on - Heart rate slows down because of the temperature change, not the water."


    Basically it seems to me to be saying that while there are very well known physiological responses triggered during freediving they have nothing to do with some innate diving ability given to us by aquatic ancestors and evolution, but instead extraneous factors such as colder temperatures, pressure, stress, lack of oxygen etc. I dont think it denies that things happen in our body as we dive that allow us to hold our breath longer, but more that these responses are your body trying not to die, rather than some romantic "dive response" or "aquaticity" evolved into us we haven't tapped till we go diving.



    You're missing the point. It's a physiological response that is well studied and documented. You can call it a reflex or response or that dive thingy...it doesn't matter. Everything your body does is geared towards it not trying to die.


    The Mammalian Diving Reflex

    Quote from Hardline

    You're missing the point. It's a physiological response that is well studied and documented. You can call it a reflex or response or that dive thingy...it doesn't matter. Everything your body does is geared towards it not trying to die.


    The Mammalian Diving Reflex


    I understand completely. Im pointing out that the article doesn't discount those physiological responses, but rather the reasons they are triggered. Hes arbitrarily separating the romantic concept of "the aquatic ape / dive response" from the boring "our bodies do stuff in cold water to not die" which he even accepts as real. Hes just trying to dispell the romantic idea im sure some freedivers have that were designed to hold our breath by evolution and diving for clams as monkeys. Probably in an attempt to remove some of the bs about how safe and wonderful and natural deep diving is.

    Drop a baby in the pool. It holds its breath and swims to get on its back. Then dcf comes to take your kid but the lesson is still valid. It is programmed in to us

    i like to spear fish

    Quote from LunkerBuster

    Drop a baby in the pool. It holds its breath and swims to get on its back. Then dcf comes to take your kid but the lesson is still valid. It is programmed in to us


    But "it" in your example is only the instinct to avoid water, float, and hold ones breath when submerged. Not the ability or instinct to "dive deep" past residual volume etc, which is what that article is talking about. I dont think anyone would disagree with the fact that weve got water


    I dont know why such a strawman is being made of the author position. To me he seems to very clearly be talking about humans being programmed to dive deep. Past residual volume even. He even mentions diving shallow as apes/prehistoric humans.


    Quote

    None of all these responses has anything to do with your belief that your ancestor had the habit of diving below RV to look for food. Why would you chase after fish at depths below 30 when crabs, muscles, seaweed can be found at depths were you hardly have to equalize. And in those days there were plenty of it. Why even submerge, wait for the tide to pull back and there it is.

    Quote from LunkerBuster

    Drop a baby in the pool. It holds its breath and swims to get on its back. Then dcf comes to take your kid but the lesson is still valid. It is programmed in to us


    When Jake and Kiera (his older by two years sister) were about 3 months old I did exactly that. I bobbed up and down about 4 times, blew in their faces and "plunk"….dropped them in the water while their wide eyed mother looked on from the side of the pool. As I remember they just held their breaths and didn't move much at all. After about 4 - 5 seconds I lifted them up to see the surprised look in their faces that basically said, "why the **** did you just do that"? :D


    All animals have the instinct to swim. ehhh, with the possible exception of ants….they can't swim worth shit. Why are we the only deep free diving land mammal? I guess because we were smart enough to figure out how to do it. Then made fins, masks, rubbers for spearguns…:D

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