Tools
Sit, stand, and look away
Two habits, one timer. Neither is complicated — the reason people drop them is that nothing is keeping count.
Posture
Sitting
50:00
Eyes
Next break
20:00
The timer runs in this tab only, and nothing is stored or sent anywhere. Leaving the tab in the background is fine — the countdown is worked out from the clock, not from ticks, so it catches up rather than falling behind.
Why alternating beats standing all day
Standing desks got sold as the fix for sitting, and then people stood for eight hours and found a new set of problems in their knees and lower back. The thing that helps is changing position, not picking a better one to hold indefinitely. If you only take one number from this page, it is that the switch matters more than the ratio.
What 20-20-20 is for
Focusing at one distance for hours is what leaves your eyes aching by the evening. Every twenty minutes, look at something about twenty feet away for twenty seconds, and the focusing muscles get to relax. A window helps. A wall at the other end of the room will do.
Starting cadence
Fifty and ten, if you have no strong opinion. It is the gentlest split that still counts as alternating, and it survives contact with meetings — which is the only test that matters, because a routine you abandon in week two is worth nothing. Move to thirty-thirty once standing stops feeling like an interruption.
If standing is uncomfortable at any cadence, the desk height is the usual culprit — check it against your height.