Study Tests Whether Morning Caffeine Can Make You Mentally Sharper - Video

A new study suggests that a 300 mg dose of caffeine may not improve morning cognitive or reactive agility performance in young men who consume little caffeine regularly.

Published in Nutrients, the study examined 51 healthy, recreationally active men aged 18–30 who typically consumed less than 150 mg of caffeine daily. Participants completed laboratory tests after taking either 300 mg of caffeine, a placebo, or no pill in a randomized crossover design.

The researchers assessed several aspects of morning performance, including memory, attention, executive function, reaction-related agility, body temperature, mood, tiredness, hunger and sleep-related measures. Caffeine did not improve morning performance.

Researchers found no clear differences in cognitive performance between the caffeine, placebo and no-pill conditions.

Reactive agility was also unaffected. Among the 27 participants who completed the agility testing, caffeine did not significantly change movement time, cognitive-motor efficiency, movement-time variability or the number of successful responses.

The researchers also found no meaningful effects on rectal or skin temperature. Similarly, caffeine did not significantly alter hunger, fullness, cravings, energy, sleepiness or subjective tiredness. Mood measures and caffeine withdrawal symptoms were also comparable across the three conditions.

The results suggest that 300 mg of caffeine taken about an hour before morning testing may not provide a performance advantage for young men with low habitual caffeine intake.

However, the researchers caution that the findings cannot be generalized to everyone. The study involved only young males, the agility analysis included just 27 participants, and testing was performed while participants were fasted.

Further research is needed to determine whether caffeine affects morning performance differently in women, habitual caffeine users, elite athletes or people with different chronotypes.

REFERENCE: Edwards, B. J., Giacomoni, M, et al.; (2026). Effects of Acute Caffeine Ingestion on Morning Temperature, Mood, Reactive Agility and Cognitive Measures in Males: A Standardized Approach. Nutrients. 18(17). DOI: 10.3390/nu18172771,