I can't back up my claim with where I got the information at the moment, but I do believe that this is a bad idea and may result in injury, decreased accuracy or both.

Work instead on strength training (like Motownhonkey said). Get yourself a bowfit or go to the gym. Do some reasearch on exersizes for the rotator cuff. They're the closest thing to strengthening the muscles used to draw your bow that you'll find I believe.