Health and Test Performance: How Exercise, Nutrition & Sleep Affect Your Score

Your health has a direct impact on your test score. Exercise improves cognition and lowers anxiety sensitivity. Nutrition determines whether your blood sugar stays stable throughout your exam, or whether it crashes mid-section. And sleep is the foundation of cognitive ability, which makes learning, memory, and emotional control possible in the first place. 

If you’re studying for the GMAT, GRE, or EA and you’re only thinking about content review and practice tests, you’re missing the biggest boost to your performance that’s available to you: your health.

Below, we cover how each of these physical factors affects your performance, what the research says, and where to go for deeper guidance on each one.

Exercise: The Cognitive Edge You Might Be Skipping

Regular exercise, including exercise before an exam, can lead to measurable improvements in your test scores. Research shows that people with higher fitness levels score roughly 10% higher on tests of learning, reasoning, and problem-solving. Exercise also reduces “anxiety sensitivity” by regularly exposing you to the physical symptoms of stress (elevated heart rate, perspiration, rapid breathing), so those same symptoms feel less threatening when they show up on test day.

We’re not saying you have to become a gym rat. Even twenty minutes of focused effort will help you see tangible results that you’ll feel on test day. Bodyweight exercises like push-ups, squats, lunges, and burpees work with no equipment and minimal space, and the endorphin payoff will help you get through any study session.

For the full research on why exercise helps and a step-by-step guide to getting started, see How Exercise Can Boost Your GMAT Score. For advice from our fitness expert Kyle Krancher on fitting workouts into a packed study schedule, see How a Fitness Coach Can Boost Your Test Score.

Nutrition: What to Eat Before and During Your Exam

Food is fuel, and the quality of that fuel determines how well your brain performs under pressure. The core principle is simple: every meal should include all three macronutrients (fat, carbs, and protein) so your blood sugar stays stable. Carbs are digested quickly, while protein takes the longest to digest – combining them into a healthy, balanced meal keeps you satiated and focused through multi-hour exam sessions.

One important note: don’t skip breakfast on test day! During study breaks or even during the exam, reach for snacks that combine at least two macronutrients to make sure you’re fueled well to concentrate.

There’s also a direct connection between gut health and anxiety. An imbalance in gut bacteria can contribute to mood disorders, and a diet low in fiber and high in inflammatory foods makes that imbalance worse. The food you eat during your prep matters immensely, so make sure to take care of your health as you navigate your studies.

For detailed guidance from our nutritionist Brandee Hommerding, including meal prep strategies for busy students, see What to Eat on Test Day.

Sleep: The Foundation Everything Else Depends On

Poor sleep negatively impacts memory, creativity, and logical reasoning, exactly the skills standardized tests demand. Research consistently shows that you need at least 8 hours of sleep per night when performing at a high cognitive level. Only about 5% of people can genuinely function well on less than 7 hours of sleep – you don’t want to incorrectly assume you’re one of them, and end up with weaker performance on test day because you haven’t been sleeping enough.

The key is consistency: a good sleep plan is something you build in the days and weeks before your exam, not something you try to achieve the night before. A consistent schedule, a regular evening ritual, daily exercise, and a balanced diet all compound into better sleep quality.

If you feel tired after waking, drowsy throughout the day, or reliant on caffeine to function, your sleep probably needs work. For detailed advice from our sleep consultant Shannon Glenn, including what to do about test-day insomnia, see Sleep Before an Exam.

Sorry, But Performance-Enhancing Drugs Won’t Help

If you attended an undergraduate program in the United States, you probably know that academic PEDs like Adderall and Ritalin are common among university students. The pitch sounds appealing: take a pill and hyper-focus while you study. But hyper-focus is actually a bad thing on tests like the GMAT and GRE.

These exams reward flexible reasoning across multiple solution paths. Stimulants cause cognitive tunnel vision: you speedily pick the first solution path that comes to mind, even if it’s inefficient or a dead-end. The result is rushed choices, careless errors, and stubborn obsession over unnecessary details, exactly the opposite of what you need.

For an honest, non-moralizing breakdown of why academic PEDs tend to hurt rather than help standardized test scores, see Why PEDs Won’t Help Your Test Score.

Caffeine: Friend or Foe?

Caffeine is a performance-enhancing substance in its own right, and it affects everyone differently. In general, caffeine raises cortisol, the fight-or-flight hormone that elevates heart rate and blood pressure. If anxiety is already a factor in your test performance, that extra cortisol can amplify nerves rather than sharpen focus.

The practical advice: if you normally drink coffee, test day isn’t the time to change your routine, but it also isn’t the time to double your dose.