High G-Force Centrifuge Training - 12G protocol. High-G training is done by aviators and astronauts who are subject to high levels of acceleration ('G'). It is designed to prevent a g-induced loss of consciousness (G-LOC), a situation when the action of g-forces move the blood away from the brain to the extent that consciousness is lost. Incidents of acceleration-induced loss of consciousness have caused fatal accidents in aircraft capable of sustaining high-g for considerable periods. The value