Most of us would pass out with head-to-toe G forces of just 4 or 5 because our hearts can’t summon the necessary pressure. Blood pools in our lower extremities, and our brains fail to get enough oxygen.

Has G-Force killed anyone?

It’s difficult to calculate the exact level of G-force that would kill a human, because the duration of exposure is such an important factor. There are isolated incidents of humans surviving abnormally high G-forces, most notably the Air Force officer John Stapp, who demonstrated a human can withstand 46.2 G’s.

Normal humans can withstand no more than 9 g’s, and even that for only a few seconds. When undergoing an acceleration of 9 g’s, your body feels nine times heavier than usual, blood rushes to the feet, and the heart can’t pump hard enough to bring this heavier blood to the brain.

Is G-Force harmful?

An upwards acceleration of about 5g is enough to overwhelm the ability of your heart to pump blood to your brain. This causes oxygen starvation and you will black out within a few seconds. Downward, or negative, g-force is even worse.

For example: An acceleration of 1 g equates to a rate of change in velocity of approximately 35 kilometres per hour (22 mph) for each second that elapses.