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decrease heart rate after strong effort under water

Discussion in 'Search & Rescue' started by curamax, Jun 26, 2019.

  1. curamax

    curamax Registered

    # of Dives: 200 - 499
    Location: México
    I'm doing my rescue diver certification,
    and the dive master told me about this: heart rate , after doing a very srong effort dont go down to normal , that in order to bring back to normal heart rate, you need to complete stop , in other words you have to stop moving .

    For example, in land, if you are running fast and your heart rate go high , you just slow down and your heart rate its going to come down . but in the water its not that way, you have to complete stop doing efforts .

    I want to know for 2 reasons ,
    1) underwater , its very common that your heart rate raise when you dive with dives with very strong currents , when you move from one spot to another with current , so for that matter I take 1 or 2 minutes the recovery my breath , so I dont consume my oxigen .

    2) the other reason , is in triathlon race, many times you start swimming very fast , so your heart rate goes high very fast , and doesnt go down even if you slow down the speed ( i did check in my training in a swiming pool ). and it happen that way
    and for that matter aprox 75% of people who died in triathlon races died in the swimming stage ( first one) maybe its for that reason?

    Can some one tell me if thats right ?

    ( I hope I explain my point the right way )

    Bubblesong likes this.
  2. The Chairman

    The Chairman Chairman of the Board Staff Member

    # of Dives: I just don't log dives
    Location: Cave Country!
    Your heart rate is tied to CO2 levels. It's much, much harder to get rid of CO2 at depth. On the surface, it's harder to breathe due to water pressure on your chest. You're creating CO2 just trying to breath.
    curamax and MargaritaMike like this.
  3. caruso

    caruso Banned

    # of Dives: 200 - 499
    Location: Long Island, NY
    Never mind my mistake
  4. curamax

    curamax Registered

    # of Dives: 200 - 499
    Location: México


    Good to know that and why it happens
  5. jadairiii

    jadairiii Contributor

    Hate to say this but it is not actually the case. You can "warm down" while swimming and bring your heart rate way down. Same way we would also warm down running, by running after a race. You will have to stop to get it to "resting rate" but that is obvious and that is with any type of exercise.

    What keeps your heart rate up is lack of conditioning. More out of shape you are, the longer it takes to get your heart rate down. If we do hard sprint sets in the pool we will always follow them up with a slow, easy 100 yard/meter swim to bring down the heart rate.

    Problem with Tri races, most people dont warm up prior to the race or when they start dont start easy and warm up during the race. Its not the swim that is killing them, its going balls to the wall without warming up. If the bike or run portion was first, that would kill the most. In every distance swim race I have done (5 and 10+K), I always take it out easy if I have not warmed up first. I will always catch the "rabbits" that go out fast and fade fast.

    And that is what often is happening underwater when people overexert. They are out of condition/shape, (and as stated above the increase WOB of scuba) so they build up a lot of CO2 and cant get their heart rate back down, not because of the CO2 but because of the lack of conditioning.
    leavenotrace and jejton like this.
  6. curamax

    curamax Registered

    # of Dives: 200 - 499
    Location: México
    Thanks jadairiii

    I’m training to do one Ironman , so I think I’m in good shape , you we're right about bring down the heart rate with a slow easy 100m swim ,
    but in my case it takes me alot more time to slow down the heart rate when swimming than when running or biking,
    so, because of that , I also start searching another possibilities and this is what I found :

    How Diving Affects Your Health and Circulatory System | The Heart & Diving - DAN Health & Diving

    So, what I understand, about this, is that in the water , there are few effects can affect your heart,
    and been in a good shape or good condition helps to prevent problems and also to slow down faster heart rate
  7. pantheraba

    pantheraba Registered

    Be sure a heart arrhythmia is not involved. Look up Wolf Parkinson White syndrome. I had a martial arts student who experienced similar symptoms that you describe and at 15 years old he discovered he had an arrhythmia. He thought the fast beating heart was normal and it wouldn't slow down for a long period of time. It took two ablations to correct the situation and he was fine after that. It is not only exercise that causes excessively fast beating heart rates.
  8. ginti

    ginti Contributor

    # of Dives: 200 - 499
    Location: Lyon, France
    Hi @The Chairman, sorry to reply to such an old thread... but I am very interested in understanding the link between CO2 and heart rate. Could you articulate a bit? Or give some links, even to a Wikipedia page? Thanks :)
  9. The Chairman

    The Chairman Chairman of the Board Staff Member

    # of Dives: I just don't log dives
    Location: Cave Country!
    CO2 elevates anxiety and anxiety elevates your heart rate as well as your blood pressue. Pretty simple. A Google search gave a multitude of links that support this: does co2 elevate your heart rate? - Google Search
    chillyinCanada and ginti like this.
  10. jejton

    jejton Contributor

    # of Dives: 50 - 99
    Location: Florida
    Heartrate is linked to oxygen consumption. Work harder, need more oxygen, cardiac output increases. It increases by increasing the rate of pumping and/or the efficiency of each pump (Cardiac output = stroke volume x heart rate; stroke volume is the amount of blood ejected with each contraction). Very high CO2 levels can cause cardiac arrest but that is not the issue being asked. CO2 levels are linked to the rate of respiration as that is the main way for a body to remove CO2. CO2 also affects blood flow to the brain. If you hyperventilate and lower your CO2 below a certain threshold, blood flow to the brain will decrease. That can cause syncope (passing out) and is actually used in certain emergency situations medically.

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