Gravity on the Moon is one 6th of that on earth. Gravity on Mars is one 3rd of that on Earth I beleive? Low g enviroments are not good for the human body because they cause bone degeneration and muscle loss. Anyone living in a base on these planets could be weighted down with something heavy, Equipment and or clothes, to simulate the force of gravity on earth. If you do disagree, why do you think that this is a bad/impractical idea?