I don't have an "arm" day and mine measure about 19" at 215 pounds...The secret is compound movements - bench, deadlift, and squats....Yes, squats.

On deadlift/back day, I only do two sets of light preacher curls to failure as the last lift. After deadlifts, rows, pulldowns, chins (all pulling movements) your bis should be feeling it if you lift with intensity. I could probably do without the preacher curls but it is like icing on the cake after a nice back workout.

On bench day, I follow pressing with a max of two heavy sets of skull crushers with a spotter and a last drop set to failure. I usually get two sets of 10 at 185 and drop set at 135 on this and it hits the tris real nice after all the pushing chest movements.

On squat day, just forget about isolating any upper body muscle. You should be focusing on your legs but your entire body will benefit.

You push yourself to the max on these three lifts and your arms will have no choice but to grow.

Remember, "Arm" day is for nancy lads like upondeez who won't do all their compound movements through the week like they should