Break the information into small chunks first. Study a little at a time. Think small bites that you can digest, not so much that you choke. SLEEP! That’s where long term memory consolidation happens. A nap is less detrimental than you might think
According to my hectic routine, I usually take break for 5 minutes after 45 minutes delving (study). And for an hour after 2 hours of being bookworm. Well, I must say that you need to take glucose and water after getting much absorbed in books. Other criterions include staying to the topic, conceptual cramming, practicing and etc. Well, let me know about yours..!?
I use the student/teacher method, if you can’t explain something to a five year old.. you don’t fully understand it yourself. So git gud