Bench dips concentrate on wrecking your shoulders. No joke. Charles Poliquin on www.testosterone.net said this and ask anyone who knows about strength training and they will tell you the same thing. My old training partner fcked up his shoulders from doing these also after I told him not to. Just look at the bad position that your shoulders are in , they are stressed backwards obviously. There are plently of better exercises to do for triceps out there, dont wreck your shoulders doing this bullshit exercise.
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