I've been using Dvorak (Type 2 with some modifications such as mapping the various types of parens to alt gr + homerow) for the last few months and it's helped me a lot, too. More than I expected, actually. The last few weeks I've been working very long hours due to ending up double-booked with customer projects (one got delayed) without any trouble, which wouldn't have been possible previously. The amount of travel is drastically reduced.

It's not the only measure I'm using: I've been using an MS Natural Keyboard Pro for years, which certainly didn't solve the problem entirely.

I haven't noticed correlation with exercise, but I'm willing to believe that doing none at all is bad for you. (I exercise semi-regularly)