If you really want to hit your shoulders/forearms hard, ty this, its a brilliant, home made excersise i read about on another forum, thout i'd share it with you...Get a bar (can be a disused dumbell without weights or a piece of wood or whatever), and hang some weight from it with rope or strong string or whatever, i'm doin about 30lbs at the mment). Then, using an overhad grip, try to roll the string round the bar, bringing the weight up...trust me, after a few ups and downs, you'll feel your shoulders and forearms BURNING!! its great, i love it. Couple of tips though, put a cushion or something underneath, just in case the string breaks, and watch your toes!! let me know what you think...enjoy
-sam
-sam