We've all experienced the 3 PM slump. You sit down to do a past paper, and your eyelids suddenly weigh a thousand pounds.
1. The Light Trick
Your circadian rhythm is controlled by light. If you are studying in a dim room with just a desk lamp, your brain produces melatonin (the sleep hormone). Turn on all the overhead lights, or better yet, study near a window with natural sunlight.
2. Strategic Caffeine
Drinking coffee at 6 PM is a terrible idea because it has a half-life of 6 hours, meaning it will ruin your sleep tonight, making you more tired tomorrow. Instead, use 'caffeine naps'. Drink a cup of coffee, immediately set a 20-minute alarm, and sleep. When you wake up, the caffeine will just be hitting your bloodstream, and the nap will have cleared out adenosine (the chemical that makes you sleepy).
3. Active Engagement
You fall asleep because reading is passive. If you switch to actively doing past papers on RevisionGrid or testing yourself with flashcards, your brain has to work, which keeps you awake.