Hey, I know that feeling, too!
My PhotoReading course included the book Natural Brilliance by Paul Scheele. In it, he gives splendid advice on how to get out of Stuck States, like I had been experiencing, and you seem to be encountering.
Now my colleagues wonder why I draw little broken Stop Signs next to the more dreary tasks on my To Do Board
Check the book out, even if you read it like a novel - it has done wonders to my satisfaction witn life in general, and decimated my far-too-long-for-far-too-long To-Do List.
With Physical Exercise, I'd say: Stick To It.
PhotoReading has taught me to say: Have Fun!