What can be expected if we lived on a heavier planet? The stress on the body would resemble weight lifting on this planet wouldn't it? I'm not sure if muscles would grow stronger or just die on us and even if we did grow stronger if our bodies would get worn out quicker. I'm wondering if we would have any other troubles biologically? After some generations we'd develop an equilibrium like we have here on Earth when we are at rest wouldn't we? How much of a gravity boost can the average person handle before they just can't even get themselves off the ground? Would everyone end up being ripped or would our muscles change so that they don't have to be as big as they do on Earth to be as strong? Would it affect our height and size at all?

 

And of course, the reverse. If we stayed under light gravity for a prolonged time like on the moon, would there be any health risks?

Under heavy gravity, we would have more air pressure and more oxygen. This is generally a good thing. The thicker atmosphere would block more radiation, so cancer should go down.

 

If the gravity is too strong, going aquatic may be a solution.

Under heavy gravity, we would have more air pressure and more oxygen. This is generally a good thing. The thicker atmosphere would block more radiation, so cancer should go down.

 

If the gravity is too strong, going aquatic may be a solution.

Yeah, I agree with you, but having more oxygen is not always a good thing. Having more oxygen increases the rate of oxidation process, and that would be a serious problem for our internal organs, because high oxygen concentration would cause their dissolution.

Oxygen (in air) has very strong oxidative features, but high concentration of nitrogen (N) is a factor that "reduces" this feature. And if it weren't for nitrogen, our internal organs would dissolve because of oxygen's high oxidative features.