pull down to refresh
I've ran both structured and unstructured - depends on the job I'm running.
I have had years of waking up before everyone else, use my best time of the day to do strategically important work, then do 10-12h of meetings, process emails in breaks, then go to bed. And in the weekends do only the first item and have the rest off because no meetings. This works efficiently if you have wide responsibility and you get to recharge on the weekends.
Currently though, I have zero meetings. All my comms with clients/colleagues/3rd parties are at most chat, often async though, like email or GitHub issues/PRs. Worse, where I formerly had teams of hydrocarbon, I now have silicon, which never sleeps, so I have to intrinsically manage it from my own cycle, rather than what I am used to: adapt to other people's cycles. So I think it is mostly a discipline issue.
My wife seems to prefer to run her life between burned up candles and is convinced that she cannot operate any other way, and as a very proximate observer it often does not look as effective as she thinks.
There have been times in my life where operating between burnouts has felt most effective.
There are other times when a more balanced lifestyle leads to better outcomes. Especially when considering thought work, or creative endeavors.
I'm not convinced any of us can meaningfully change the way we operate, though.