It seems so simple but why does it appear that so many self-described serious/Stotan runners neglect to keep one? For me, it was because I was too lazy. It has been repeatedly shown by runners greater than us that keeping track of all things relating to your training is essential. Consider the following:
"One of the reasons why athletes stop running,or training, is that they lose their belief in future development. Without a training journal, the athlete cannot see the pattern of training that preceded his own best performances and his own best seasons. Nor can he see the differences that led to poor performances and poor seasons. The diary keeps track of the quality and quantity of training and allows one to plan on which of these should be emphasized depending on event and time to train. Evaluations, predictions, comparisons, and future planning can be made with greater accuracy and reliability as a result of information accurately recorded in a diary. The benefits available are well worth the relatively small effort involved in the daily upkeep of a diary."