In THIS article Dorian Yates describes eight items he feels are required to have the perfect training session. Keeping a journal is the one that stuck out the most to us.
That leads us to what I feel is one of the most valuable tools in creating perfect workouts, the training log. I used my journal to write down goals and workouts every day from when I began bodybuilding in 1984 to the day I retired after the 1997 Mr. Olympia. Every month in the off-season, I would choose about 10 key exercises like the incline barbell press, barbell row, leg press and so on and set a goal for how much stronger I wanted to be in a month’s time.
In addition to writing down all my workouts, I entered my meals and even my energy levels and moods. Every so often I would go back and study these pages, looking for trends. If I noticed that something was producing results, I kept it. If something else didn’t seem to be effective, I discarded it. This allowed me to gain a much better understanding of the various foods, exercises, techniques and so on that my particular body responded best to, so I could fine-tune my entire program.
In addition I would always consult my training journal immediately before leaving my home to go train. I would retreat into my office where it was quiet, and review my last few workouts and my goals. I noted the exercises I had done last time for the body part I was about to go train, how much weight I had used, and how many reps I’d gotten. I would then write out the workout I was about to perform, with all the same details. - Dorian Yates