Hi mate,
I have the opposite problem.
I cant train biceps and triceps in the same workout or I get pins and needles in my hands. when I go to bed they go numb. But this only happens when I am obsessed with the tape measure.
My best arm pump comes from:
CARB UP
Lots of rice for tea night before workout day, high carb breakfast, loads rice lunch, mars bar 30 to 40 mins before workout. Drink lots of water during the load up.
BICEPS TRICEPS PUMP WO
Superset 1 ( Do four times )
Dips 12 reps to failure superset with 2 arms together seated dumbell curls slow squeeze hold 2 sec at top
Superset 2 ( Do 3 or 4 times )
Triceps cable push downs 10 reps to failure superset with straight bar cable curls on rower. Bar to forehead. Slow.. hold each rep 2 sec at the top.
Never more than 1 min between supersets and never more than 20 sec rest from tricep to bicep movement.
I have managed to pump my poor arms up a whole inch on the tape measure using the above.
Please not that the workout is only to pump to measure arms. Does it make them grow? Don't know. I don't do it often enough to tell.
Have fun