I'm going to assemble my panel of experts and see if I can come up with a valid explaination for this malady. This is what we know so far, the two common demoninators are; muscle growth and sleep. Some folks have stated that they have numb arms even though they don't do AS. But they do work out heavily. Everyone indicates that this only occurs during sleep. If it were as simple as blood pooling in the muscle after excerise then the numbness should occur anytime we put our arms over our head for an extended period. Example, I went to the pool yesterday afternoon and laid on my back for an hour with my arms extended above my head, no numbness. What's missing? Sleep! Personally, I don't have these problems if I'm not taking AS. I think the mechanism behind this is much more complicated that we're guessing, and if anyone out there whom may need a Graduate disertation could have just hit a goldmine.