... at least, not for me. The bottleneck is something like mental energy. I can only make progress on a (subjectively) difficult topic for a handful of hours (at best) each day before hitting severe diminishing returns, and being forced to "relax" for the rest of the day.
In light of the above, the obvious thing to optimize for the sake of "making progress on difficult things" is the amount of "mental energy available per day", not "waking hours available per day". Sleep seems to serve the function of "restoring mental energy"; but I get diminishing returns on sleeping longer (in a single block) as well; for me, there doesn't seem to be a big difference in "available mental energy" during a day whether I'd slept 6 hours or 9 hours.
So, since I'm getting diminishing returns on both my waking and sleeping hours, the obvious thing to try is to split the day up into multiple "sub days", i.e. some form of polyphasic sleep. Ideally, I'd like to spend a larger total fraction of the day asleep; this contrasts things like "the Uberman's sleep schedule", where the goal is to have as much waking time as possible (which, through this lens, is pure folly).
Have any of you (or anyone you know) had any success with something like this?
im very interested in things in this domain. its interesting that you correctly note that uberman-sleep isn't a solution, and naps don't quite cut it, so your suggested/implied synthesis/middle-ground of something like "polyphasic but with much more sleep per sleep-time-slice" is very interesting.
given this post is now 2 years old, how did this work out for you?
in a similar or perhaps more fundamental framing, the goal is to be able to effectively "reset"; to reattain if possible that morning/new-day magic. to this end, the only thing ive found that even comes close to the natural reset of sleep is a shower/bath. in a pinch, washing/dunking the head/face in water can work, but less well. for this reason I often take two showers a day. usually the pattern is: walk+workout, shower, work, get tired, walk outside for 30ish minutes, shower, work some more. the magic isn't fully restored for that second session, but more than if i just walk without the shower.
if the 'full magic' of true/natural morning can get me 4 hours of Hard Work, then the shower-reset can maybe give me another 30mins to an hour. more work is performed than just Hard Work, but I think you know what I mean.
some people will say workouts/exercise help, but for me they don't in themselves. ie, in the more natural setting of "part of the normal waking up and/or general health routine", of course exercise is a must. but from this framing of "how to get more of the morning/new-day magic", i've found more exercise is counterproductive. even trying to just shift around *when in the day* the exercise is done is counterproductively draining for me; morning is best. not to mention that delaying the workout is a great way to never actually workout since i don't really want to do it at all; the chance i do it at all is maximized in the morning.
okay, also, while im talking about this:
the goal is energy/new-day-magic
so one sub goal is what the OP and my previous reply were talking about: resetting/regaining that energy/magic
the other corresponding sub goal is: retaining the energy you already have
to that end, I've found it very useful to take very small breaks before you feel the need to do so. this is basically the pomodoro technique. I've settled on 25 minute work sessions with 3 minute breaks in between, where I get up, walk around, stretch, etc. Not on twitter/scrolling/etc.