A little background: I'm a Division 1A speed athlete, powerlifting state and national record holder, previously highly ranked endurance athlete, exercise science major at a top US university.
From my intense, but obviously limited training background and studies I have come to an interesting (to me at least) insight. While science can apparently explain many of the physiological adaptations of the human body, there is often discrepancies between an individual's training and his or her performance. For example even though an athlete is following a seemingly perfect protocol for his or her goals down to perfection, he or she isn't making the progress that is wanted. But on the other hand, when the same athlete isn't following such an intense program, or isnt following it so strictly, he or she often makes better progress.
Both from my experience and from talking to others this seems to be the case quite often. For example when I go out to parties one to two times a week for an extended period of time I find that my lifts and various performance indicators excel faster than if I wasn't going out and enjoying myself so much, while on the other hand when my life revolves solely around training my performance often suffers. And while the science indicates the intense ergolytic effects alcohol (and other drugs), the practical application of these isolated studies doesn't line up.
I feel that the psychological aspect of training and balance between one's training and enjoying life, relaxing, is of prime importance to an effective program. Why not write party nights into training, why not train hard the next day while thinking about the good night you just had and about how awesome life is. It seems to me that many of the top coaches around preach to stick to the plan all the time (save maybe a cheat meal or two a week), but I find both from my experience and from talking and observing some of the world top athletes that balance in life is as important as the training program itself to athletic or any physical success.
In my opinion, training should be fun (most of the time), and if it loses its fun it isn't worth it.. If training becomes one's life and it isn't enjoyable then its time to reevaluate.
I am interested in all your thoughts.