Question on muscle growth?

I was working out 6 times a week. Days 1, 3, 5 were biceps, forearms, triceps. Days 2, 4, 6 were chest, upper-chest and shoulders and have a protein shake after my workouts. Well lately I've been working out less, like 1-2 times a week and still drinking my protein shakes after my workouts and have noticed actually my muscle getting a lot bigger and faster than they were. Why is this?

your giving them more time to heal

I know i work with this every day of my life

Because you allowed your muscles more time to recover and allow themselves to repair. You were overtraining, and not giving them enough time to build back up after tearing em apart at a workout. Most muscle groups only require 1 day a week of training to build muscle. The longer you give them to recover, the bigger they get. Long as you stay consistent with your workout, nutrition, and sleep,

askscooby.com is a bodybuilding forum. check it out if you actually want to get into this kind of stuff, probably the best site out there for home bodybuilders.

Im a bodybuilder

Because 6 days in a row of arm and shoulder workouts is too much work. Your body needs rest.

You didn't ask specifically, but I have to comment on that routine... 3 days a week of curls, tricep extensions of some kind, and direct forearm work are a monumental waste of time. Bench, row, overhead press, chin ups, a couple sets of curls if you absolutely have to, and call it a day. Where are your leg exercises? Squat! Deadlifts and powercleans are good forearm/grip work.