Doing the high G manuvers cause blood to flow to your head, or a low point in your body (your butt.)
High G pulls blood away from your brain and low Gs force blood too your brain.
Repeating the manuvers cause some streching of the veins. (This is generally Bad, especially forcing a lot of blood to the brain.)
The Straining exercise restrict the flow of blood, the muscles press on the veins and arteries. Thus slowing the flow of blood from the brain or too it. So muscle training helps, and therefore with practice you can resist blackouts to some extent.
Now, blood vessles are generally fragile, and ofter burst under the strain.
Hence all the stunt pilots that have blood shot eyes, and nose bleeds easily.
Even now, there should be something in the game, if you pull too many Gs it should be fatal.
------------------
"I could feel the 20MM Cannon impacting behind me so I made myself small behind the pilot armor" Charlie Bond AVG
lkbrown1@tir.com
http://www.tir.com/~lkbrown1 Very Opinionated Person.