Don't you mean 20 sets per bodypart? I usually only do 1 exercise per body part for 3 to 4 work sets. Remember... COMPOUND EXERCISES PWN ISOLATION EXERCISES. I'm convinced that those who do isolation exercises do them motivated by and based upon fear. Once again, 2 of the widest shoulder fellas dat I knew NEVER did any isolation delt work, in fact they didn't even do any kind of overhead pressing. Just so you know dat wot I say is true, one of these fellas is semi-famous and you can see how wide shoulder dat he is, his name is JM Blakley. Type his name into google image search and you will see wot I'm talkin' bout.