Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: neilep on 03/10/2012 00:48:26
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So,
A Triathlon is a protracted three-sport athletic competition consisting of a swim, then a cycle and finally a run !
Although deaths are rare they usually occur in the swimming section
Why's that then ?
In A Triathlon, Why Do Most People Die In the Swimming Event ?
whajafink ?
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Water can be pretty unforgiving.
According to this, the USA had about 9 deaths in 2010 in triathlons. (http://www.washingtonpost.com/national/health-science/deaths-in-triathlons-may-not-be-so-mysterious-panic-attacks-may-be-to-blame/2011/10/24/gIQA70NrKN_story.html) There are quite a few events with a lot of participants, but that just sounds unacceptable for any sporting event.
I've never run a triathlon, but I have had a 2-leg cramp away from shore in salt-water. It was disturbing. According to the article above... Panic? I suppose, perhaps it is in part how one deals with something like a cramp, fatigue, or other injury.
I'm seeing a few notes on portable life-jackets.
http://www.dcrainmaker.com/2012/05/myswimit-safety-device-good-or-bad-for.html
Read the comments in the second link.
I'm surprised the device isn't designed in the proper location right into the wetsuit, but perhaps an advantage of having it in a pouch is that it can be shared. Anyway, it might be worthwhile to require something like portable inflatable life jackets for first-time participants, and encourage others to carry them, as much to get them distributed in the group as anything else.
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Is sheepy going to enter an Iron-ram?
In a general sense, whilst swimming is a good form of exercise it is not entirely risk free.
I do a lot of openwater swimming (not Tri's they are a bit too much like hard work) and I am a swiftwater rescue technician, so have learnt a little bit about the risks associated with cold water.
When swimming hard in a race, it is quite easy to over exert yourself - and simply not get enough oxygen into the body, this can lead to heart failure. This can be compounded if you miss a breath or swallow water.
There is also, on entering the water, the cold shock reflex triggered by rapid skin cooling - this can be reduced by conditioning yourself, but it is a reflex so cannot be eliminated entirely. It is the sudden gasping intake of breath when first entering cold water and can lead to hyper-ventilation. Part of the cold shock reflex is vasoconstriction - the blood vessels contract. This makes your heart work harder and can lead to heart failure particularly if you demand that it starts windmilling arms and kicking legs to win (or at least compete in a race)
When you have survivied Cold Shock your body has to deal with the temperature change - water is far more effective at cooling you down than air and a wetsuit simply slows this process. Your body's natural reaction is to reduce the blood supply to the extremities in order to maintain core temperature. Doing so reduces the amount of oxygen avaliable for the muscles to work and will eventually lead to swim failure (aka cold incapacitation) where it is simply not possible to use your arms and legs to keep yourself afloat. It is a misconception to say that people who fall into icy water die of hypothermia in the water in x minutes, but they do drown in x minutes because their limbs stop working.
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Water can be pretty unforgiving.
According to this, the USA had about 9 deaths in 2010 in triathlons. (http://www.washingtonpost.com/national/health-science/deaths-in-triathlons-may-not-be-so-mysterious-panic-attacks-may-be-to-blame/2011/10/24/gIQA70NrKN_story.html) There are quite a few events with a lot of participants, but that just sounds unacceptable for any sporting event.
I've never run a triathlon, but I have had a 2-leg cramp away from shore in salt-water. It was disturbing. According to the article above... Panic? I suppose, perhaps it is in part how one deals with something like a cramp, fatigue, or other injury.
I'm seeing a few notes on portable life-jackets.
http://www.dcrainmaker.com/2012/05/myswimit-safety-device-good-or-bad-for.html
Read the comments in the second link.
I'm surprised the device isn't designed in the proper location right into the wetsuit, but perhaps an advantage of having it in a pouch is that it can be shared. Anyway, it might be worthwhile to require something like portable inflatable life jackets for first-time participants, and encourage others to carry them, as much to get them distributed in the group as anything else.
Thank ewe so much Clifford for your very informative post.
I can only imagine the terror that occurs when ewe have BOTH legs spasm like that !...... I get the occasional spasm/cramp in my leg and it quite literally hurts like a word that ewe can imagine the censor net will deny here !!
I think the idea of a life saving device is very good. I do note that it's been mentioned that it may lull people into a false sense of security but I think n the case of a competition it will be far from ya consciousness whilst ewe just concentrate on winning. I agree for the leisurely swimmer that it may have that effect but I think in this case the benefits far outweigh the negatives.
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Is sheepy going to enter an Iron-ram?
In a general sense, whilst swimming is a good form of exercise it is not entirely risk free.
I do a lot of openwater swimming (not Tri's they are a bit too much like hard work) and I am a swiftwater rescue technician, so have learnt a little bit about the risks associated with cold water.
When swimming hard in a race, it is quite easy to over exert yourself - and simply not get enough oxygen into the body, this can lead to heart failure. This can be compounded if you miss a breath or swallow water.
There is also, on entering the water, the cold shock reflex triggered by rapid skin cooling - this can be reduced by conditioning yourself, but it is a reflex so cannot be eliminated entirely. It is the sudden gasping intake of breath when first entering cold water and can lead to hyper-ventilation. Part of the cold shock reflex is vasoconstriction - the blood vessels contract. This makes your heart work harder and can lead to heart failure particularly if you demand that it starts windmilling arms and kicking legs to win (or at least compete in a race)
When you have survivied Cold Shock your body has to deal with the temperature change - water is far more effective at cooling you down than air and a wetsuit simply slows this process. Your body's natural reaction is to reduce the blood supply to the extremities in order to maintain core temperature. Doing so reduces the amount of oxygen avaliable for the muscles to work and will eventually lead to swim failure (aka cold incapacitation) where it is simply not possible to use your arms and legs to keep yourself afloat. It is a misconception to say that people who fall into icy water die of hypothermia in the water in x minutes, but they do drown in x minutes because their limbs stop working.
YAYY !!.. thank ewe Mazurka for your wonderful reply !
Moi ?..do a tri ?...lol.....in my high heels ?
Your explanation of the shock syndrome and the clarification of the effect on the body helps me understand it very well. Is there a similar effect when one leaves the water too ?.....still full of adrenalin and moving on the next event ?...No 5 minute break to dry off and change eh ?
That is really fascinating about the loss of movement over hypothermia/ic reaction and it makes perfect sense. Thank ewe very much.
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(no problem - I do occasionally get annoyed about the dieing of hypothermia in cold water thing - indeed there are a couple of cases - most notably Anna Bågenholm where hypothermia has actually prevented drowning -http://youtu.be/jLr15BBBtrc (http://youtu.be/jLr15BBBtrc) is a clip from a BBC Horizon documentary about it)
There are issues when you get out of water after a prolonged period - although I am unsure whether they would affect Triathletes.
There is a very complex physiological response known as circum rescue collapse - which I belive was a phrase coined 70 years ago in relation to recovering downed airmen from the sea. Briefly, if you remove a casualty from water vertically, they will suffer from a sudden loss of blood pressure that often leads to heart failure. This relates to the body's response to the pressure of the water, (the pressure 1m below the surface is aproximately 100mbar greater than at the surface) pooling of blood, the effects of the cold and the stress of needing rescuing! However if the casulaty is removed from the water horizontally, this is far less likely to occur.
I think that the drop in blood pressure is probably on a spectrum so at the milder end it manifests iteself as "jelly legs" when you get out the water and perhaps, combined with the adrenaline/ cortisol of a race situation could trigger heart trouble during the transition.
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" In A Triathlon, Why Do Most People Die In the Swimming Event ? "
Because we are land animals?
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So it says in the good book (or at least the good book that had "already supplanted the great Encyclopaedia Galactica as the standard repository of all knowledge and wisdom") Many were increasingly of the opinion that they'd all made a big mistake in coming down from the trees in the first place. And some said that even the trees had been a bad move, and that no one should ever have left the oceans.
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(no problem - I do occasionally get annoyed about the dieing of hypothermia in cold water thing - indeed there are a couple of cases - most noticeably Anna Bågenholm where hypothermia has actually prevented drowning -http://youtu.be/jLr15BBBtrc (http://youtu.be/jLr15BBBtrc) is a clip from a BBC Horizon documentary about it)
There are issues when you get out of water after a prolonged period - although I am unsure whether they would affect Triathletes.
There is a very complex physiological response known as circum rescue collapse - which I belive was a phrase coined 70 years ago in relation to recovering downed airmen from the sea. Briefly, if you remove a casualty from water vertically, they will suffer from a sudden loss of blood pressure that often leads to heart failure. This relates to the body's response to the pressure of the water, (the pressure 1m below the surface is aproximately 100mbar greater than at the surface) pooling of blood, the effects of the cold and the stress of needing rescuing! However if the casulaty is removed from the water horizontally, this is far less likely to occur.
I think that the drop in blood pressure is probably on a spectrum so at the milder end it manifests iteself as "jelly legs" when you get out the water and perhaps, combined with the adrenaline/ cortisol of a race situation could trigger heart trouble during the transition.
Thanks again Mazurka !
That is a fantastic clip by the way.... incredible !! and how interesting with reference to the manner of alignment that a casualty is removed from the water. I just googled "circum rescue collapse" and retrieved some very interesting info/guides.
Thanks again
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" In A Triathlon, Why Do Most People Die In the Swimming Event ? "
Because we are land animals?
Thanks BC..........you'd think that even though we are land animals we'd also have the ability to be natural swimmers !... After all , we're surrounded by water (though I know we live on the land)....we fish in the water and we originally came form the water........Evolution should have left us with an affinity for the ocean !
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Thanks Neilp..........you'd think that even though we are land animals we'd also have the ability to be natural fliers!... After all , we're surrounded by air (though I know we live on the land). Evolution should have left us with an affinity for the atmosphere!
To be fair we are very good generalists.
Compared to other animals that climb trees, we swim quite well.
For reasonably good swimmers, we are very good runners.
For good runners we do a very good job of climbing trees.
Pretty much the only thing we are bad at is flying.
But, when it comes down to it, if you get cramp on land, you fall over. If you get cramp in the sea you drown.
Also, we are well equipped to lose heat- we have little hair (well, ewe might have plenty...), and we have the most successful sweat glands in the animal kingdom.(That's not something to brag about in a night club- trust me).
The counterpoint to that is that we are rather susceptible to the cold.
Water is a poor conductor of heat, but it's a great deal better than air. It also has a large heat capacity so it's very good at chilling you.
We are warm blooded- getting too cold really messes us up- especially our brains and without the processing power of the brain we are in real trouble.
So, if we leave our normal habitat and go somewhere rather cold then exercise pretty much to the point of collapse, we are pushing out luck.
Sometimes, the luck runs out.
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Thanks Neilp..........you'd think that even though we are land animals we'd also have the ability to be natural fliers!... After all , we're surrounded by air (though I know we live on the land). Evolution should have left us with an affinity for the atmosphere!
To be fair we are very good generalists.
Compared to other animals that climb trees, we swim quite well.
For reasonably good swimmers, we are very good runners.
For good runners we do a very good job of climbing trees.
Pretty much the only thing we are bad at is flying.
But, when it comes down to it, if you get cramp on land, you fall over. If you get cramp in the sea you drown.
Also, we are well equipped to lose heat- we have little hair (well, ewe might have plenty...), and we have the most successful sweat glands in the animal kingdom.(That's not something to brag about in a night club- trust me).
The counterpoint to that is that we are rather susceptible to the cold.
Water is a poor conductor of heat, but it's a great deal better than air. It also has a large heat capacity so it's very good at chilling you.
We are warm blooded- getting too cold really messes us up- especially our brains and without the processing power of the brain we are in real trouble.
So, if we leave our normal habitat and go somewhere rather cold then exercise pretty much to the point of collapse, we are pushing out luck.
Sometimes, the luck runs out.
Thanks BC...great response.
As far as I'm aware we crawled out from the ocean and there I guess spawned the gamut of air, sea land dwellers etc etc.......so..I do see your point.
It all boils down then to the effect on the body from air to water during a triathlon competition (and of course just social partaking of the sea)
The answer then lies in insulating the body against the shock and the addition of safety equipment as cited above by Clifford
Thanks again.
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There is, of course the Aquatic Ape Hypothesis (http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis).
Where do the deaths occur? Do any individuals get "trampled"?
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.washingtonpost.com%2Frf%2Fimage_606w%2F2010-2019%2FWashingtonPost%2F2011%2F11%2F14%2FSports%2FImages%2FAP0506190222.jpg&hash=7f2ec08a0e4fbe55c9b48b59eaa8b3bd)
http://www.washingtonpost.com/national/health-science/deaths-in-triathlons-may-not-be-so-mysterious-panic-attacks-may-be-to-blame/2011/10/24/gIQA70NrKN_story.html
A heart attack is dangerous anywhere. It could be quite dangerous cruising at 20+ MPH on a bicycle, possibly on narrow curvy roads. But, one may in fact get quicker first aid on land, even on a bicycle, and of course, one would be less likely to get one's lungs filled with water too.
Cold water could be a culprit. I have experienced the rapid loss of strength from swimming in very cold water. It is scary. Hopefully most of the triathlons are done at more reasonable temperatures that don't sap the energy. Do athletes train in the open water, or in pools?
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An annual attempt to evolve homo aviansus in Melbourne, Australia:
Fortunately, this competition has a good ratio of competitors to lifesavers...