You should probably consult a doctor before attempting to emulate any behavior seen on DBZ. Your skeletal system could definately take it for short stints. I'm thinking your cardiovascular system would be the first thing to fail. Your heart and the valves in your veins would probably wear out if you spent any significant amount of time in such an environment, as 2Gs would mean twice the systolic blood pressure!
http://www.nym.org/healthinfo/docs/014/doc14.html
Also, if you tried to do more than 15-20G, even for an instant, you would probably die in a very spectacular and disgusting way.
