I tested this at age 18 with comprehension tests. The figures escape me but at a pace that was sustainable for no more than 45 minutes, if I recall like 900 wor

I tested this at age 18 with comprehension tests. The figures escape me but at a pace that was sustainable for no more than 45 minutes, if I recall like 900 words a minute, my comprehension dipped down all the may to mid 70%. But that was roughly 2.5x the pace you would read a textbook at. Maybe more. Worth it? I don't know. But if its meaningless calories, sometimes just finishing helps. There is a ton of day to day "reading" in the form of emails and whatever you do on a computer. For everything else its context dependent.