How to Boost Your Brain Before an Exam: Simple Science-Backed Tips

You’ve studied for weeks. You know the material. But right before the exam, your mind feels foggy, your fingers are cold, and your thoughts won’t stick. This isn’t laziness. It’s your brain hitting a biological wall. The good news? You can reset it in under 30 minutes - no caffeine bombs, no last-minute cramming. Here’s how real students in Dublin, London, and Sydney actually boost their brainpower before a high-stakes test.

Move your body for 10 minutes

Walking briskly for 10 minutes increases blood flow to your prefrontal cortex - the part of your brain that handles focus, decision-making, and memory retrieval. A 2023 study from University College Dublin found that students who did a short walk before an exam recalled 22% more facts than those who sat still. You don’t need to run. Just walk. Outside if you can. Even pacing your hallway works. The goal isn’t fitness - it’s oxygen. Your brain uses 20% of your body’s oxygen, and when you’re sitting, you’re basically starving it.

Chew gum - yes, really

Chewing gum isn’t just a habit. It’s a cognitive hack. The act of chewing triggers increased blood flow to the brain and stimulates the hippocampus, which controls memory. A 2024 meta-analysis of 11 studies showed students who chewed sugar-free gum during the 15 minutes before an exam scored 15% higher on recall tasks. Pick a flavor you like - peppermint or mint are common - but avoid sugary gum. Sugar spikes your blood glucose, then crashes it. You want steady energy, not a rollercoaster.

Drink water - not coffee

Dehydration kills focus faster than all-nighters. Even a 2% drop in body water reduces short-term memory and attention span. Most students think coffee is the answer. But caffeine only works if you’re not already dehydrated. And if you’ve been drinking coffee all week to stay awake? You’re probably already dehydrated. Drink 300ml of cool water 20 minutes before the exam. Not a cup. Not a bottle. 300ml - about one and a half standard glasses. Sip it slowly. This alone can improve your reaction time and reduce mental fatigue during the test.

Use your hands - not your phone

Scrolling through TikTok or checking messages right before an exam floods your brain with dopamine hits. That’s the opposite of focus. Instead, do something tactile. Scribble key formulas on paper. Trace diagrams with your finger. Fold a piece of paper into a tiny square and hold it in your palm. These simple physical actions activate the motor cortex, which helps lock in memory. One student in Galway wrote her essay outline by hand on her arm with a pen. She said it stuck better than any flashcard. Your hands are connected to your memory centers. Use them.

Smell peppermint or rosemary

Scents trigger memory more powerfully than any other sense. Peppermint and rosemary have been shown in lab settings to increase alertness and memory recall. You don’t need essential oils. Just chew a peppermint candy or rub a drop of rosemary oil on your wrists 10 minutes before the exam. If you’re in a testing center that bans scents, bring a peppermint tea bag. Suck on it. The scent alone is enough. A 2023 study at Trinity College Dublin found that students exposed to peppermint aroma before a psychology exam performed 18% better on recall questions than those who weren’t.

Take three slow breaths - not five

Deep breathing calms your nervous system. But most people do it wrong. They take long, slow breaths and think that’s enough. The real trick? Exhale longer than you inhale. Try this: Breathe in for 3 seconds. Hold for 1. Breathe out for 6. Do it three times. That’s it. This activates the vagus nerve, which lowers cortisol (your stress hormone) and shifts your brain from panic mode to focus mode. No meditation apps needed. No apps at all. Just your breath. Do this right before you walk into the exam room.

Don’t review your notes

This is the biggest mistake. Trying to cram in the final 10 minutes doesn’t add new knowledge. It overloads your working memory. You’ll forget what you already know. Instead, review your mental map. Ask yourself: What are the three big ideas I need to remember? What’s the one formula I always mix up? What’s the structure of the essay I’ll write? Visualize the answers. Don’t read. Imagine. Your brain stores memory by association. If you can picture the page where you wrote that equation, you’ll recall it faster than if you reread it.

What not to do

Don’t drink energy drinks. They spike your heart rate, then crash your focus. Don’t eat a heavy meal. Your body will divert blood to your stomach, away from your brain. Don’t compare yourself to others. Someone else’s calm doesn’t mean you’re behind. Your brain has its own rhythm. And don’t try to memorize new facts. You’re not a sponge anymore. You’re a conductor. Your job now is to play the music you already learned - clearly, confidently, and calmly.

Real student example

Emma, 17, from Cork, was failing her biology mock exams. She studied 6 hours a day but always blanked during the test. Her tutor told her to stop reviewing and start moving. She started walking for 10 minutes before each exam, chewing peppermint gum, and drinking water. She didn’t change her study schedule. She changed her pre-test routine. Her next grade jumped from a C to an A. She said: "I didn’t know more. I just remembered more."

Final checklist: 5 minutes before the exam

• Walk briskly for 10 minutes (if you have time)
• Chew sugar-free gum
• Drink 300ml of water
• Smell peppermint or rosemary
• Take three slow breaths (inhale 3, hold 1, exhale 6)

That’s it. No extra apps. No magic pills. Just biology. Your brain isn’t broken. It’s just waiting for the right signal. Give it oxygen, movement, scent, and calm - and it will deliver.