> (4) Low exercise. Daily exercise levels and hence stress on the skeletal
> system would have been greater in our stone age ancestors - increased
> physical stress on bone tends to increase cross sectional area and
perhaps
> (equivocal data) bone mineral density.

Movement is essential to life:-)
If we dont sweat, how do we get rid of our extra proteins from the milk?
( Magnesium or garlic would help this process).
Motion also would help the digestion, the .....

-martinf.