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Why am I so Sleepy after diving?

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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New Member
Aug 9, 2002
I've heard of the blood shunt and all, but after my Thursday diving, where I do negatives and the like (by the way, My training buddy, Marcel, did a 55second negative at 12ft yesterday...wow) I am so sleepy a little later. I used to get this after diving during work, but I haven't had it happen until I started doing longer negatives @ 12 ft. I was sooooo sleepy an hour after I got home. What can anyone tell me about this?

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It happens to me also sometimes, after diving and freediving, or even after training statics, but only if I don't get to a point when I fight the urge to breath (high BP & pulse). If I do a "hard" workout, It does'nt.
Sometimes it's drowsiness, and sometiems it's just a good Buzz...
I just took it naturaly. Interesting quesiton.
what do you mean "do negatives" ?

whats that ?

antt arrak
from estonia where are't freedivers :)
Negatives are where you exhale before diving rather than taking a deep breath before doing the dive.

Its called negative because you are negatively boyant ie no (or little) air in the lungs. Or have I completely missed the mark?:confused:

The drowsiness is most likely due to oxygen starvation or low average oxygen levels. On long haul flights (trans-pacific etc) the airlines actually reduce the amount of oxygen in the cabin atmosphere to get people to go to sleep. Not something they admit to readily but it is a reasonably common practice. According to an airline steward I know anyway..:hmm

You also burn a lot of calories and have a huge adrenaline hit when diving. So as your blood sugar and energy levels decrease and the adrenaline wears off you get sleepy.
Youve come to the right place! Heaps of knowledgable people around here. And some top notch divers. Pity I'm not amongst them..:eek:

And on behalf of DB: Welcome to our Estonian friend!:)
On long haul flights (trans-pacific etc) the airlines actually reduce the amount of oxygen in the cabin atmosphere to get people to go to sleep.
I heard that the pressure inside the plain is reduced to 0.8atm or so for some reason, but I didn't think about the "benefits" to the passenger.

Say, so maybe tranatlantic flights are a good train for freedivers, making the body adapt by producing more hemoglobin?
Should I go dive straight after the flight? :)
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