I do heavy shrugs...I start at 135-25 then 225-25 then 315 for 10 (correctly) then i go up in weight and do a 5 by 8 heavy...barbell shrugs...
if you are lucky enough to have a gym with a seated shrug machine, that you can load plates on, use that because you can not really cheat by using your whole body to bring the weights up, but you still have to use good form...
i agree with farmers walk and deads..but even though your loading weight on for deads, you generally dont do enough reps when doing deads to effectively hit the traps good enough in my opinion...if your going to do deads, why not throw in some trap work after your done with your deads providing your not blown up from the dead workout...
i find dumbell presses are ok, but i see to many guys in the gym trying to use to much weight when doing them and they dont get the effectiveness of the exercise...not to mention most guys look as if they are doing uncline presses as they do them anyhow..
my .02
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