I'm finishing-up my participation in the "May Productivity Challenge" that E was running in DS|CAFE! Here is the distillation of what I learned:
I only have a certain number of daily startup credits that are used to initiate focus tasks that I have COMMITTED to do. The sustainable number of tasks is 3 credits per 24-hour period with a hard stop time of 5PM.
Cashing in a startup credit uses some brain stamina. So long as there is some brain stamina available, it is possible to restore a small percentage of it with limited snacking, unplanned interesting tasks of no longer than 30 minutes, and unfocused time related to eating a meal, enjoying one's space, or doing self-care activities.
After using the first 2 startup credits for the day, I generally need 3-4 hours of unfocused time before I can use another credit.
I can do up to 5 credits if I carefully manage the reserve of brain stamina that I have, but this will push the stop time past 5PM. This disrupts the amount of unfocused time I need at the end of the day, approximately 7 hours, before I can naturally fall asleep early enough so I can wake up early and maintain a regular sleep schedule.
When my reserve of brain stamina is completely used-up this causes my ability to focus to collapse. Executive function and emotional regulation is severely compromised as my brain enters a stimulation seeking mode to restore it. Because this is a kind of starvation response, it is no longer possible to fall asleep and get the rest that would restore brain stamina. When in the disregulated state of mind, impulsive behaviors like overeating, buying stuff, scrolling through social media, mindlessly playing games or watching movies without any sense of enjoyment are likely. The period ends only when the mind and body are so completely exhausted that it's possible to pass out.
I didn't know that I had a "startup credit limit" until after starting the May Productivity Challenge. I had picked three challenge tasks per day day, which meant that I was having to cash-in five or more credits. The net effect was pushing out the time that I am able to fall asleep because I need around 7 hours of wind-down time doing random stuff before I am relaxed enough. If I screw up and enter brain starvation stimulation mode, then I am unable to rest well at all. I'm just finishing my second task of the day now and it is 1130PM...I won't be able to fall asleep for another 3-4 hours if I am lucky, and I will probably wake up exhausted and unable to focus. While this is unfortunate, it's a great takeaway that I'll be able to use for achieving OPTIMAL DAYS within the envelope of my capacity!