Reprint
I posted this one a few months ago.
Here's a good 4-arm routine. Do it with 90 second rest intervals, and superset the last set of one exercise with the first of the next exercise, and you'll get it done in like 10-15 minutes. I do it with my Tris/Bi workout.
1. Hammer curls w/ Dbell: I usually curl them into my chest, instead of straight up & down.
1 warmup set
1 workset of 15 reps
2. Reverse-Grip Preacher Curls w/ straightbar: These are the best exercise for 4-arms you can do in my opinion. Use a short straightbar if your gym has one.
1 warmup set
1 workset of 10-15 reps
3. Wrist Curls(Dbell or Straightbar): I prefer the bar. I use the end of a bench to do them. I also squeeze my inner thighs against my arms, in order to brace them. I don't believe in extending the fingers when doing these, but if it works for you then fine. The key is to go just heavy(or light) enough to get 15 good reps. Do them quickly, so as to get a burn. Pause at the top.
2 sets of 15
4. Wrist Curls behind-the-back(straightbar): Same theory as regular wrist curls.
2 sets of 15
5. Reverse-grip wrist curls:. I use a Utility Bench to do them. Doing them with your arms on your knees on the end of a bench doesn't brace the forarms well enough in my opinion. Just get a utility bench, and lie your forarms across that. Use a quick pace, with a pause at the top. 15 good rep principles apply here as well.
2 sets of 15.
6. Standing dbell wrist curls: Standing w/ Dbell at your sides, simply curl them into your thighs. Pause at top. Quick pace. Get a burn!
2 sets of 15
I know that sounds like a ton of work, but I always use the first set in each lift as a warmup pretty much, so it kinda cuts the amount of hard sets in half, if you want to look at it that way.
At the end, I like to do a few sets hanging from the parallel-grip pullup bar, just for some additional grip work. Maybe I'll do a set of wrist rope rolls too, but I don't think those are all that productive. Maybe as a burnout set at the end, but in my opinion, you won't get cut forarms if you would rely on that exercise as a core in your 4arm routine.