I started doing this in 2015. I had to quit my job and go back to consulting. I found that somewhere around 12-20 hours per week of knowledge work was peak eff

I started doing this in 2015. I had to quit my job and go back to consulting. I found that somewhere around 12-20 hours per week of knowledge work was peak efficiency (output versus effort). Unfortunately, from 2020 to now, I have had to work closer to full time and I'm less fit, less efficient, suffering from poorer sleep. I am hoping to get back to ~15 hours a week by mid-year this year.