This depends on what you mean by “stand”.
- Do you mean stand up without falling over?
- Stand up without losing consciousness?
- Stand up without dying?
- Or stand up without becoming a bloody pulp of organs and bones?
Let’s start with the easiest one: standing up without falling over.
That’s not too hard, as long as you have good balance and coordination. You can probably handle a few Gs of acceleration in any direction, as long as it’s not too sudden or prolonged.
Maybe up to 10 Gs if you’re really fit and trained.
Next, standing up without losing consciousness.
That’s a bit trickier, because your brain needs a constant supply of oxygen-rich blood to function properly.
If you accelerate too fast or too long, the blood can either pool in your lower body or rush to your head, causing you to black out or red out.
The limit for this varies depending on the direction and duration of the acceleration, but generally speaking, it’s around 5 Gs for head-to-foot acceleration and 9 Gs for chest-to-back acceleration.
These are the limits for trained fighter pilots wearing special suits and performing anti-G maneuvers. For untrained civilians like you and me, it’s probably much lower.
Now, standing up without dying.
That’s where things get really interesting. You see, your body is not designed to withstand extreme forces that can tear apart your tissues, rupture your blood vessels, damage your organs, or fracture your bones.
The limit for this also depends on the direction and duration of the acceleration, but according to some sources , it’s around 46 Gs for constant acceleration over more than a fraction of a second, and around 100 Gs for a brief impact or collision.
Of course, these are the limits for survival, not for comfort or health. You’ll probably suffer from severe injuries, internal bleeding, organ failure, or brain damage if you experience such forces.
Finally, standing up without becoming a bloody pulp of organs and bones.
Sorry to disappoint you, but there is no limit for this. No matter how strong or resilient you are, there is always a force that can crush you like a bug.
14 Gs of lateral acceleration can tear your organs loose from one another. Imagine what 1000 Gs would do to you. Or 10,000 Gs. Or a million Gs. You get the idea.