And if all else fails, wash and slightly dry your hands every few minutes. The dampness makes your tension tighter but, of course, will probably also chap your hands. So be sure to slather on the lotion at the end of your knitting session.
On the bright side, you can count your trips to the sink as exercise! In fact, add ankle weights and tote your fully-loaded knitting bag back and forth each trip! And that, my friends, is how you combine knitting and exercise!