I have completed my FIRST 90 days of P90X! I feel so accomplished to make that statement because I am also making a validation that I am still doing the workouts. It was tough! Some days I would ask why am I torturing myself. The workouts are still a challenge but you do notice you can do more and that you are doing it better. I am seeing more definition and that also pushes you to continue. I played around with the program a bit and did several weeks of doubles. Doubles was rough and not for the faint of heart. Doubles can also give you a sense of burnout too. Anyone interested in the program I would say go ahead and start because you can and will master the moves. I will not guarantee you will be ripped and cut your first 90 days, but you will be new and improved. I have no regrets and feel stronger and better from all the struggles and sweating. Keep in mind also, hydration and clean eating are imperative to progress and performance, because gang, this is NO JOKE! It's the X! P90X!