Originally Posted by Couch
21's can be effective. I use to do them when I first started and did see some decent improvement. I'll occasionally throw in one set of them just for the pump.
Its amazing how hard they can be to do.. when I started I think I started with 15 or 20lbs.. I can do them with 35-40 lbs now, but anything over that is more tiring than its worth lol I usually stay between 25-35 lbs on them to keep good form