Reserve an extra gear - this is another technique used by successful people when they face tough challenges, basically this is just a mindset, this is just a metaphor but when you watch champion athletes or hear the story of legends you will see that they always finish strong, they always find ways to win when they are in deep trouble. It seems like they have a bag of reserve energy that they use when defeat is occupying their vision. It seems like they have an extra gear that they use when the ending is near.
This also should be your mindset, you should have an extra gear when the going gets tough. Most people gave up at the end, they don't know that just a little more effort and perseverance will ensure their victory but because they can no longer find an energy to keep going they give up.
There is no better way to have an extra gear than to practice will power. There are methods how to strengthen your will power and it is up to you how to choose a method that best fits you, may it be visualization, affirmation or any kinds of method that will fuel your willpower. If you will ask me how I strengthen my willpower, I use self talk, when I am in a tough situation I just find thoughts that will replace the negative emotion or will make me forget that I am in pain. Some of the thoughts that I use when I am in pain were: "I am doing this for my family", "Just one more step, one more", "I am so lucky coz I can move, I have only one life I have to use it to the fullest", "Tomorrow is not guaranteed I have to give my best now". Those were the thoughts that I use when I feel like giving up and I am glad that they are still working up to now.
So next time when you have to face a big challenge always reserve an extra gear...prepare...make sure there is something that you can substitute for pain so you can finish the race, make sure there is an energy that you can find when your eye for victory is going blind.