One way to tackle the increasing load is becoming a more efficient reader. Timothy Burke at Swarthmore College writes about college reading in particular, and offers the following helpful and humorous advice:
"The first rule, in some ways the only rule, is skim, skim,
skim. But skimming is not just reading in a hurry, or reading sloppily,
or reading the last line and the first line. It's actually a disciplined
activity in its own right."
Skimming should give you an idea of the structure of the piece (book, article, etc.) to move on to finding the central concepts and the sequence of the arguments.
You should, of course, also read the footnotes, of which there are five different basic kinds: 1) Logrolling; 2) Weird little stuff that distracts from the main point but which is still kind of interesting; 3) Oh, by the way, there's one teeny tiny little exception; 4) Look, Ma, I did the reading; and the 5) You want proof? I'll give you proof footnotes.
Also, even if it seems cumbersome and time-consuming,
"if a term recurs regularly in a text, or seems particularly central, you MUST
learn to pick up a dictionary and find out what the author means. Learn to keep
one by your side and don't try to bluff your way past such a term. An initial
mistake about the meaning of a term can rapidly multiply into a gigantic
misreading if you're not careful."
Last but certainly not least, take notes and prepare for discussion.
Read more - even skim! - at Staying Afloat: Some Scattered Suggestions on Reading in College.