We argued with my nephew that he was organizing his time incorrectly. I want to say that in studies you need to take breaks, then the information is better remembered. But don't take breaks on a smartphone or watching TV, as he usually does. It's necessary to take useful breaks. I found many options for this https://booksrun.com/blog/7-easy-tips-for-study-breaks/
article. It seems to me that you need to be able to combine physical activity and mental activity. It's very important. How do you think?