Not to mention stretching in between sets can be a great growth aid. This is fairly hard stretching, moving even more nutrient rich blood to the muscles being worked.
-------------- As far as genetics go, the skies the limit. You are limited only by your mental perception of it.
Look how animals are like dogs or the big cats in the wild. What do they do every time they get up.....they stretch there muscles out so that they are ready for anything.
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thats a good observation-i didn't see it in that light before...