
Originally Posted by
Jason Donaldson
This really screams to me to check your valsalva. Holding it in your face, not against the glottis can contribute heavily to this. I adopted a "war face" kind of approach to work against this: I bare my teeth when I valsalva, as a way to make sure my lips are parted. It's easy to slip into the Dizzy Gillespie style, though, so it takes constant, vigilant practice.
That said, I still get light headed from heavy grinds. Putting a hand on a stable object helps. Taking a knee is a good preventive measure. Sitting down is fine.
Maintaining tension, especially in the legs, instead of a sudden release of everything also helps. The one time I ever outright blacked out was upon the release from a heavy pin press, years ago in a public gym. I woke up almost immediately on my rear, back against the mirror (I face out whenever possible). I was only out very briefly - I knew this because I know where in the music I was listening to I heard last and upon coming to - and the first thing I did was look around to make sure nobody saw it... It seems that putting the bar on the pins allowed me to relax suddenly, which I think exacerbates the blood pressure drop that leads to syncope.
The head rush is cheaper and safer than doing drugs, at least. Well, once you learn to manage it...