Success is simply never giving in to failure - either in mind or body.
The sprint is like life ... blink and you miss it.
A mind filled with negative thoughts makes you feel miserable and inadequate and will lead to failure after failure no matter how hard you try to succeed.
If you have positive energy you will always attract positive outcomes.
It is one thing to know what should be done, it is another to do it.
You have to create your self-belief by going to your core to find the probable reasons for the negativity in you, and then demolish them.