In a controlled crossover study of 51 recreationally active young men with low habitual caffeine intake, researchers tested whether 300 mg of caffeine taken about an hour before morning testing affected cognition, mood, temperature, appetite, and related outcomes, with reactive agility assessed in 27 participants. Caffeine did not improve cognitive or reactive agility performance or meaningfully alter mood, tiredness, appetite, or thermoregulation under the study conditions.
