Assuming force being applied along the axis of the spine, and that it continues, you would experience tunnel vision, lightheadedness, loss of consciousness, and

Assuming force being applied along the axis of the spine, and that it continues, you would experience tunnel vision, lightheadedness, loss of consciousness, and eventual death. People can't really handle more than 5g on that axis without a special g suit. Lesson: Don't try to take it standing up.