A while ago I began focusing on training my back according to CT's principles (initiate motions be feeling the lats/traps, holding the squeeze, etc).
My problem is that my biceps consistently become fatigued before my back. This is particularly noticeable on higher rep sets. My lats & traps are no where near fatigue, but my biceps reach complete failure.
For a description of my drop-off rate, here is the last DB curl workout I did (at the end of my deadlift/back workout). Yes, the numbers fall really fast. I stopped just short of failure on each set, and I do about a 2-second negative. 50#x8, 45#x9, 35#x7, 25#x7
Aside from adding in some higher rep curls throughout the week, does anyone have suggestions for how to improve my bicep endurance?