G-tolerance is something you develope, you cannot just strain at the right
time and stay awake.
Back when I was younger and in excellent physical condition, I did
aerobatic training. Sustained or repeated G's will quickly drain you with
each successive maneuver. I never did enough to go to sleep, but repeated
4-5 G maneuver's caused be to gray out for several seconds (the instructor
was then in control of the aircraft).

How do pilots like Sean Tucker and Patty Wagstaff sustain G loads for their
entire routine?

I know Tucker "takes a break" half-way through his, doing a long climb out
while he catches his breath (or clears his head), but, still -- they seem to
be under incredibly high Gs for a large portion of their 15 minute routines.

I've only had one aerobatic flight, pulling a maximum of 4 Gs that lasted
maybe ten seconds, and even that was a pretty good workout. I can't
imagine doing that -- and far more -- every few seconds for 15 minutes!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"