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Blood presseure

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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New Member
Oct 29, 2001
I have a qustion for the fysisists out there :D

I have a fearly low blod pressure, not dangerously low, but definitely in the lower range for my age... I often get dizzy when getting up from my sofa etc too fast...
Can this effect my freediving? How? Is there someting I should considerate having this?

I am not a Physicist, but Alun is.....

Yes it might affect your freediving. To start with, it may reduce your tolerance to hypoxia compared to ther people, since the ppO2 in your brain may be lower than others. This is a fairly big factor.

Do you have a noticeably reduced performances compered to your peers?

I always get dizzy as well when standing up after sitting down for a while it usually lasts around 20sec. I actually walked into a wall whilst trying to work out what was going on. So how do you get a higher blood pressure.

Re: I am not a Physicist, but Alun is.....

Originally posted by Ben Gowland
Yes it might affect your freediving. To start with, it may reduce your tolerance to hypoxia compared to ther people, since the ppO2 in your brain may be lower than others. This is a fairly big factor.

Do you have a noticeably reduced performances compered to your peers?

Hi Ben!

No, as I am fearly new to the sport, and whilst spearfishing not pushing it too much, I have not noticed anything compered to my peers... On the other hand: I am not a 5 minute-man....:D

I am not too familiar with the english termes... what do you mean with hypoxia?

Regards North
a physiologist is probably better qualified to answer this question than a physicist.... but here's my input anyway for what it's worth....

i experience this occasionally too, and i think my BP is about normal. keeping well hydrated should help maintain your BP. try drinking lots of water (to start with), i mean about 1-2 litres over the course of an hour, and then see if you get the same symptoms. you should feel noticably less dizzy when standing up.

lately, i've been going to the gym in the morning. initially, i didnt bother drinking at all, because i was only doing weights (my last drink was the night before). i would get a little light-headed when getting up from a machine - i was dehyrated. now, i drink fluids at the gym (only 1 litre) and i dont get the problem any more.

i always drink 2 litres before diving to make sure i'm well very hydrated. basically, i aim to drink until i pee quite a lot. :eek: there's no need to drink loads in normal day-to-day life, just a moderate amount, but it could be a good idea before diving, or any exercise for that matter.

if you think the dizziness is severe, then it may be a good idea to talk to your doctor for some advice and get checked out.


physiologist..... of course hehehe... I know the norwegian terms better than the english, but then you wouldn`t understand... ;)

The dizzines however is not a problem, I`m just wondering how this fact can influense my diving... Is it a fact that it will limit my abilities vs other divers skills/progress?
And at what depts is it likely to be problem?
Orthostatic hypotension

Hello everyone I'm a physiologist too.North, I think your age,your blood pressure is very important.
I think you are describing orthostotic hypotension,it occurs normally in most individuals and rarely needs medical therapy but I don't know the effects on freediving,but I dont agreee with Ben Gowland,it must not effect your freediving skills too much,but the level of your hypotension is important too.
Greetings from Turkey
Consult with your doctor, but there are several methods to increase your blood pressure:
- Decrease potassium intake (within reason)
- Increase salty foods + drink tons of water
- Increase calcium intake
- Decrease magnesium intake (within reason)
- Eat licorice root (glyzyrhitinic acid) -- causes sodium retention and potassium excretion -- USE CAUTION -- and under a doctor's supervision

A person who's diet is very high in potassium & magnesium, and low in calcium & salt, will have low BP regardless of whether or not they hydrate. Further, doing lots of cardio exercise decreases your blood pressure over time.

Being light headed when you stand up can be due to three things:
1. Low blood pressure
2. Weak adrenal glands
3. Being excessively hot & vasodilated

The moment you stand up, your adrenal glands immediately secrete adrenalin compounds whose purpose is to constrict the vessels in you abdomen and maintain the blood pressure in your head. If your adrenals are weak, they will fail in their task, and you will get lightheaded even with good blood pressure.

To 'rebuild' weak adrenals, there are many books on amazon. The most common cause of weak adrenals is eating too many sweet foods (insulin spikes weaken your adrenals over time).

Eric Fattah
BC, Canada
I have the same problem. It's common in my family. When I first talked to a doctor (Air Force Flight Surgeon) about it, he told me to tense my abdominal muscles and pull them in before standing or taking the blood pressure. That was exactly the same advice that my father gave me when I was seven so that's what I told my daughter the first time I saw her knees go wobbly. By age 50 my blood pressure became normal and now I only see those ridiculously low numbers (like 80/45) when I'm recovering from a 2 hour cardio workout. When in the recovery room after surgery, O2 numbers in the low 90's seem to bother the nurses too.
In almost 55 years of diving, I don't think it has been a factor. Everone is different of course and I do think about spending 2 minutes head down before flipping right side up at 50 meters. If you find a cardiologist that can dive to 30+, he would be the one to ask.

Calcium is in milk and all that Dairy stuff. I stopped drinking milk because a while back someone was saying how the Mucus or something blocks the Eustacian (Spelling tubes) for equalizing whats the go.

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