here's what helped my traps grow like weed. First off on the day u do traps do them first. I do mines on shoulder day i do them before any shoulder exercises. Do heavy barbell rows on back day if you can add tbar rows as well. here's what i do for my traps
Barbell Shrugs
1 warm up
3 working sets, pyramiding up in weight (10-12,6-8,2-4)
1 set to failure same weight as the first working set.
Everytime i finish that burnout set and i walking to the shoulder press i keep feeling like ronnie cuz my traps are so pumped they're just sticking out of my shirt
