Whether you're a seasoned runner or are new to the sport, there will probably come a time when just running for the sake of running isn't enough. Most runners want to improve either their time, their distance, or add some other training to their regimen. Whatever the reason, keeping a training diary is a natural step in many runners' careers to both improve and see how far they've gone. Here are some things to consider:
A good first step is to go to a local library or bookstore and check out their fitness section. This can give you some ideas as to what kind of logs are out there. Will you include a section on diet and nutrition for the day? Will you be weight lifting or doing other types of exercise? Knowing these answers can help you decide what to include in your training diary and what not to include.
Now that you have a better idea of what your basic diary will look like, it's time to decide how you'd like to divide it. This will depend on just how elaborate you want to get. Do you want detailed daily information, such as breakfast, lunch, and dinner, and then your workout for the evening? If so, then you probably want a daily format, broken up into individual pages, i.e. Sunday's workout, Monday's workout, etc. If you just want a basic log of the distances you've run, then a weekly format will probably work for you. Each page can hold an entire week's worth of information, perhaps divided into columns and rows with space for distance run and at what pace.
Another thing to consider is whether you want to have your log in a regular paper book or if you'd rather keep an electronic log. Nobody says your training log must be on paper; try setting up columns and rows of what you want in an Excel spreadsheet. This can make things quite simple once it's set up. If you're someone who spends plenty of time of the computer, this may work better than pencil and paper. For those of you who prefer the old-fashioned way, a spiral bound notebook may be a good bet. It can be quite frustrating to attempt to write in a book that keeps folding over, so a spiral bound binding eliminates that hassle.
No matter what kind of training diary you choose, you will no doubt find plenty of satisfaction and inspiration when you are able to look back and see just how far you've come in your training.