Consistent sleep schedule

A consistent sleep schedule means the same wake time every day, weekends included, instead of running short all week and catching up on Saturday. The wake time does most of the work. Get up at the same hour and the body clock settles, and the sleepiness turns up on its own a few hours before you need it.

People take it up to fall asleep faster, to wake without an alarm, and to skip the Monday fog a shifted weekend leaves behind. Most were never short of sleep, only irregular: five hours one night and ten the next, an average that looks fine on paper and feels nothing like it. The cost is that it runs all seven days, so Friday and Saturday pay for it.

Nothing to buy and nothing to learn. You pick a wake time you can hold on a Tuesday and a Sunday alike, and you get up at it.

The first fortnight is the expensive part, because the body clock moves slowly and you spend a few mornings tired on purpose. After that it defends itself: the sleepiness starts arriving on time, and getting up stops taking a decision.

One late night undoes several, and the schedule has to be defended against the dinner that runs long, the flight that lands at midnight, and the Saturday when everyone else is just getting started.

That is the real shape of it. Nobody quits because the mornings were bad; they quit because holding the line costs something visible every week and pays back something only they can feel.