How do I read faster without losing comprehension?

The most effective technique is to stop subvocalizing, which is silently pronouncing words in your head as you read. Most people read at speaking speed because of this habit. Train yourself to absorb words visually rather than "hearing" them internally, which can roughly double your speed. Beyond that, use a pointer like your finger or a pen to guide your eyes across the page at a slightly faster pace than feels comfortable. This reduces regression, the habit of unconsciously re-reading words. Also practice chunking, training your eyes to take in groups of 3-4 words per fixation rather than one word at a time. Preview headings and first sentences of paragraphs before reading fully so your brain has context, which dramatically improves both speed and retention.