I used the full year training program right before my senior year of high school season up through to the beginning of my first season in college and I was very impressed with the results. In addition to seeing my pitching ability increase, my overall physique changed for the better as well. I jumped 4mph on my fastball, which may not seem like a lot, but it was enough to earn me a decent role as lefty-specialist out of the bullpen.
If anyone is contemplating purchasing the TUFF CUFF book, I would say go for it! It was definitely a worth while purchase and it helped to improve my pitching game. The only thing I added to the program was a more demanding running program which I felt did add to my stamina.
This is a great program for high school and college pitchers.