Run on grass or pavement best?

mikerox

When I run, it is sometimes on grass and other times, on pavement.
1. Which is better for my bones/joints?
2. Which gives me more of a workout?

Common sense says grass is softer and eaiser on the joints but then again, it might take more effort to run on grass?
Asphalt seems like it would be harder on the joionts, but it might be a smoother run.
The grass track is not perfectly level and I think it takes more to stay moving and upright.
But, does it hurt the feet becuase it isn't level?
It seems like I run faster in the grass because I have to lift my feet higher and prepare to land in an unlevel spot.
Seems like I can run easier on the hard surface therefore catch myself not running near as fast.

I know it sounds like I answered my own question, but does anyone know for sure?