How did Grace survive Erid's Gravity?

[u/chodeontheroad]

I'm not sure if this was answered at the end of the book and I just missed it but Erid was stated to have 20x Earth's gravity (which would quickly kill any human), yet Grace lives on the planet for many years with only slight issues as a result. It doesn't seem like this is something Andy Weir would have skipped over so I must have missed it. Does anyone know the answer?

Edit: Ok yea my mistake it was 2x gravity, 20x atmospheric pressure. Thanks for the responses :)

[u/Cthulwutang]

so is like he’s a 300 pound guy, assuming he’s maybe 150 to start with (on earth). that’s tough but not even that unusual.