Keeping a training diary enables you to look back and analyse all aspects of your running. It can help you to pinpoint, for example, why you have been injured, why you have become tired, and also why you have been running your best. Looking at when you have had your best run, you can try to reproduce this by following the same pattern of training. It can also help to motivate you to keep going with your training by illustrating the good work you have done up to your current point. If you record the time taken for a run or the distance you have covered, it can show progress in terms of running speed or distance - great if your goal is to complete a set distance, or to finish an event under your goal time.