not sure I said that but I did say it stimulates growth in the body and also working legs is HARD to it challenges and forces your body to grow because it has to. standing in front of the mirror doing curls for 30 minutes isn't so hard and your body doesn't react like it would when you work your legs. i have an article that explains more in depth over at muscle research
for this reason I like to do deads, cleans, jerks, and squats on fridays at the gym to give my body 2 days rest on the weekend. plus on friday's no one uses the squat racks (not that they use it at all very often) had a dude try and steal my rack when i went to get paper towels couple weeks ago to do shrugs lol ..
also believe it or not FISHING is a great way to stimulate growth as well.. the motion of reeling and jerking the rod working a lure ... i have been fishing all week everyday after the gym and my shoulder and arms are wasted from it. and i swear my tri's, biceps, shoulders look more ripped and bigger. not just the motion but also the evolution of the human to hunt/fish causes the mind to grow the muscle. beats sitting in front of the tv thats for sure.. why do you think people in prison build muscle? cause their mind tells them they have to to survive. when you sit in front of your computer all day or tv your mind gets lost and it tells your body to not grow because it doesn't have to to survive. weird but i believe this to be true IMHO