Gravity and the human body have a finicky relationship. Too little gravity and humanslose bone density, experience extreme nausea and become anemic. Too much gravity and humans lose consciousness and die. So how do people who experience hypergravity on a regular basis deal?
Astronauts experience microgravity while on the moon, but also hypergravity (up to 3.2 g) during take off. It’s their Earth-based friends though, fighter pilots, that experience the highest gravitational forces, up to 9 g.
Most people would pass out with 5 g (that’s why most roller coasters don’t exceed 3 g), but fighter pilots wear compression suits to counteract the forces and practice contracting their lower abdominal muscles. These serve to force the blood out of their legs and into their brain, preventing the loss of consciousness.
If a pilot descends too quickly they can experience negative g-forces. The human body is even less tolerant of these, with what’s called a redout, too much blood in the head, occurring with only -2 g.
Some animals are really good at dealing with hypergravity though. When flying in a straight line, dragonflies can accelerate with up to 4 g of force. When they turn corners, this increases to 9 g. And they don’t even need to wear a flight suit.