http://www.cactusjuice.com/blogs/archive/2007/05/09/Prison-Workout-Bicycle-Crunches.aspxThis is my very favorite abdomen workout. Bicycle crunches have helped me start to define my six pack abs. I love doing bicycles. Try 'em as part of your prison workout or just do a few sets when you wake up in the morning to help build a strong, fitenCommunityServer 2.1 SP2 (Build: 61129.2)