a will to live - A will to live is when you keep going even when you're tired

A will to live is when you keep going even when you're tired, sore, and no one else cares about your problems.

I had a will to live when I still ran the last mile of my race even though my legs felt like bricks.

My mom has a will to live because she still works even though she’s been sick for a month.

My little brother has a will to live because he still plays video games even though his eyes are red from crying.