Sure. Anything that body and mind (the animal) DON'T want to do.

For me, the most important part is observing them as they whine, plead, threaten and argue.

A very easy and millennia old way is to just sit or kneel for a predetermined amount of time. Body and mind will try anything to get you to stop once it becomes uncomfortable.

Winning this epic battle against the inner animal over and over is what I like to call soul-building.