Here, you can watch a "real man" experiencing G-LOC after failing to execute the g-strain maneuver correctly. At the top right side of the screen, there are numbers preceded by different letters. The first three, gz, gy and gx, refer to different types of g-force being inflicted on the subject during the test. Gz is gravitational force applied to the vertical axis of the body (head to toe), gy is lateral force applied to the horizontal axis of the body (shoulder to shoulder), and gx is force from chest to back. In the video, the subject is being subjected to positive gz force. Watch the number climb; he G-LOCs after a few seconds of +7.5 gees. As you can see, even after he regains consciousness he remains disoriented for a considerable period of time, including a few seconds of doing the "funky chicken", a common occurrence when "coming back" from G-LOC. If a pilot G-LOCs while flying, this extended loss of control can be disastrous:
Here's another "real man" correctly executing the g-strain maneuver and remaining conscious. You still can see the intensity of the forces experienced by the test subject, and his difficulty avoiding G-LOC. Although this man obviously has an enormous innate tolerance for withstanding high positive g-forces (30 seconds at +6.8
resting, meaning
no g-straining and
no g-suit pressure) he still describes experiencing some of the symptoms of visual system hypoxia, especially at the beginning of the test. You can also see the blood leaving his head as the forces climb, and you can see it returning to his head as the forces drop; his head goes from red to white to red again:
While the most extreme roller coasters may inflict +6 vertical gees on riders, they do it for only fractions of a second,
never for the multiple seconds you see in these tests. Hypoxia can be very dangerous and coasters that inflict G-LOC with any regularity are almost always modified (see Intimidator 305).
Also, I've only discussed positive gees in my posts. Negative gees are much more dangerous for the human body, as they cause blood to flow up from the lower extremities towards the head. Only very mild (and very short-lived) negative gees are ever experienced on roller coasters.
(My apologies for straying from the subject of Verbolten. If y'all admins want to move my posts somewhere else, feel free.)