excerpt from an article by an NPC Judge/IFBB Pro on basic principles of growth...
"A training frequency of 3 days per week (Mon, Wed, Fri) is more than enough. Numerous pros, including myself, train like this offseason for maximum growth. Even if you use streroids, you still have to train like this. steroids increase your recovery ability, but they also make you stronger at a quicker rate. The extra strength will give you the ability to train harder/tear more muscle tissue, so you will need the extra recovery that the steroids will give you."
Just because it increases recovery time, don't think people who use train more often. They usually don't.