OT: Swimming and blood pressure. WAS: Big stress test!!

[Guest guest]

wrote:

>

> ... He *finally* quit swimming, and it's never happened again. It had

> something to do with his blood pressure dropping when he changed from

> horizontal to upright; called postural hypotension. ...

>

I not going to dig up the science on this but, from what I heard, there

are reasons this happens to swimmers. One is that it is more likely to

happen when a person is dehydrated. Swimming and playing hard in water

can produce a lot of sweat, which you don't notice because of the pool

water. I have heard that competitive swimmers can loose pounds of sweat

at an event. Be careful at hot tubes too! Ever notice that you need to

pee more if you have been swimming? It may be true, because if the water

is cold it will cause the blood vessels near the skin to contract, (to

keep heat in the core of the body), which increases blood pressure

causing the body to compensate by releasing water through the kidneys.

That also adds to the dehydration. When going from horizontal to upright

blood with the body fluid moves down, due to gravity, toward and into

the legs this can cause a loss of blood from the brain. If you are

dehydrated there may not be enough body fluid to keep the blood pressure

in the brain high enough. The taller a person is the more likely this

is a problem. My son, who is 6'4 " , has fallen a number of times at the

gym (not alway at the gym's pool) because he forgets to keep hydrated

and works out for long periods. Another thing that happens at the pool

is that when in the water it puts pressure on the body, much like a

pressure suit a pilot would wear to maintain blood pressure in the brain

while fighting strong accelerations. When the pressure is released it

wants to return more blood to the limbs which can also mean less for the

brain when getting out of a pool. Problems in the pool may not be a

problem if wearing long compression socks, but who wants to do that?

BTW: I was supposed to have surgery today to remove a broken screw from

my foot and another that will probably break. They were used to hold a

joint in the foot together. I didn't even know anything was wrong. They

found them on a follow-up X-ray. I thought these things were titanium

and made to last forever. Maybe the screws are just surgical steal. In

any case I think there should be some bragging rights here for being

able to break screws with just the bones in my foot. The surgery has

been put off until next week.

notan