Although the physical training and subsequent adaptations are important, the mindset you have will also affect your performance.
In order to succeed you must develop an internal strength and resilience. This comes from a belief and confidence inside yourself. The difference between achieving your goals or not is often the degree to which you really want it. The visualisation process can improve your chances of success.
In my daily life I strive to use every situation as a means of becoming a better person and maintaining a positive attitude. I can therefore improve my decision-making and balanced perspective.
I have learnt the most from asking myself questions and recording my thoughts during and after my runs. If you are more aware of yourself, you are in a better position to work on your weaknesses and benefit from your strengths.