Repeated testing can make you faster simply because the task becomes familiar. In a study using a ruler-drop reaction test, participants improved by almost 13 ms across ten sessions, with the largest improvement early on.
That is useful if your goal is to get better at a specific reaction task. It is less convincing evidence that every kind of reaction or decision in daily life improved by the same amount.
Sleep loss is one of the clearest ways to make reaction performance worse. A systematic review of randomized studies in young adults found that sleep deprivation degraded psychomotor vigilance, and classic PVT research shows more slow responses and attention lapses after sleep loss.
Recent meta-analytic work in healthy young adults found a small beneficial effect of acute exercise on cognition and a decrease in reaction time. Other reviews suggest moderate-intensity exercise can improve response speed in several cognitive domains, although effects vary by task and exercise intensity.
A short warm-up or moderate bout of activity may therefore be worth trying before a reaction session, but it is not a guaranteed “reaction hack.”
A reaction that happens before you correctly identify the signal is just a guess. Use modes that punish false starts or require the correct choice, not only a single green-light test.
If you change from touchscreen to mouse, 60 Hz to a higher-refresh display, or one browser/device to another, part of the score difference may come from hardware rather than you. For training, consistency is more useful than constantly changing setups.
A 2025 systematic review and meta-analysis of 31 randomized, double-blind trials found that caffeine acutely improved both reaction time and accuracy on attention tasks in healthy rested adults. That does not mean more is always better: the same analysis found accuracy gains did not increase indefinitely with dose.
Reaction Lab is not giving medical or nutrition advice. If you already use caffeine, the research is interesting context; it is not a reason to consume large amounts to chase a browser score.
Continue with: Sleep and reaction time · Caffeine and reaction time · Exercise and reaction time · Gaming and reaction time.