Replying since i was searching the google ( made account jsut to answer)
Ok since nobody gets the whole gravity thing.... except from the mass / distance and whatever.... its simple like this.... If ur hand weighs 4kg.... x2 gravity is exactly liek 4x2
So if we were to live in an x2 gravity place we would have to have the energy to lift every piece of us x2 harder.... People will be shorter cause of the gravity.vs.bone material multiplication.... we would be much stronger if we came back to earths x1 gravity
much thicker bones .... (internally not exactly Exterior showing) and feel as light as a feather ( only logical cause of muscle multiplication from stronger use ).
Yes for starters humans can live in x2 gravity and take it slower to higher....
Now i saw something about heart attacks.......
Our Heart Is A Muscle..... Since it will be working harder it will multiply its muscles , and eventually will be able to withstand the force of the gravity atm....
(Astronauts get taller in outer space did u know that ?)
(Astronauts live longer in outer space did u know that?)
(Astronauts get a hard time to get used to the earths gravity again ...since less gravity in space)
(Astronauts get much weaker and slowly their bones and muscles start getting too relaxed resulting in their bones being easy to break!)
End of story not checking this post again.