Dr. Greg Rose has a segment on Upper Body Training. One of the exercises, actually four of them involving the wrists/forearms was of particular interest. It had the underhand and overhand curls but also included rotating or turning the [s]hands/wrists[/s] forearm. When doing these exercise he made the point that when doing the left side, maintain a flat wrist as you would want in your golf stroke, when doing the right side, maintain a bent wrist, again as you would want in your golf stroke.
His comments in other portions of the episode also included why you want to low weight and high reps, which made a great deal of sense to me. Simply cause and I think I recall his term correctly MUSCULAR endurance. You want to train and be able to perform for 18 holes. This he equated different from PHYSICAL stamina. Editted Not sure I totally appreciate why he made the distinction other than Stamina is a broader term and he was being specific for particular muscles.
Also he gave some interesting insight as to why when working the upper body there is more benefit to the golf stroke by doing exercise where you are standing than when lying. Balance for one, another was that while lying you are push against the bench whereas when standing you depend more on the core to maintain position and complete the exercise.
The last thing I found interesting was the length or range of motion of an exercise can help or hinder the golf stroke. For example when doing forearm presses, by only going from the side and forward limits whereas if you allow the arm to go back further, you gain more.
The episode was FIT 04-001. It might be a good watch.