endurance

• Go the distance

  To successfully complete a challenging task or competition, especially one that is long or arduous, without giving up.

• through thick and thin

  To remain steadfastly loyal and supportive during both good times and difficult periods.

• To have staying power

  To possess the ability to endure, remain popular, or continue to be effective over a long period.

• A second wind

  A renewed burst of energy or motivation that allows one to continue an effort after feeling exhausted.