ExRx.net

Until recently I always tried to perform Bent-over Laterals with the same weight and reps as regular Dumbbell Laterals (although I could always do somewhat more on the former). My thinking at the time was that I wanted my side and rear deltoids to be proportional. However, I realize now that I should be doing considerably more on Bent-over laterals, since the rear delts work in opposition to the front delts and pectorals.

Honestly, I never gave much thought to opposing muscle groups before I started visiting this sight, although my efforts to look propotional prevented me from developing any serious imbalances.