The ability to stop voluntarily protects you from being stopped involuntarily.

There are two ways to stop. One is chosen, timed, and reversible. The other is imposed by an injury, an illness, or a collapse, and it takes the choice, the timing, and often several months with it. Keeping the ability to stop voluntarily is the whole insurance policy, and it only works if you use it occasionally.

Practise stopping when you do not have to. End a session early once, take a day off in a good week. Keeping that muscle available is what prevents the version you cannot control.