The Claim

In adolescent male volleyball players with low habitual caffeine intake, a 3 mg/kg dose of caffeine administered as a capsule significantly improves simple reaction time by 9–11 ms and reduces Stroop interference time by 20–22% during morning and midday sessions, indicating enhanced psychomotor speed and executive control when baseline alertness is suboptimal.

Source: Differential Time-of-Day Effects of Caffeine Capsule and Mouth Rinse on Cognitive Performance in Adolescent Male Volleyball Athletes: A Randomized Crossover Investigation

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
64score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

In adolescent male volleyball players with low caffeine consumption, a 3 mg/kg caffeine capsule taken in the morning or midday improves reaction speed by 9–11 milliseconds and reduces cognitive interference by 20–22% during attention tasks.

See the scientific wording

In adolescent male volleyball players with low habitual caffeine intake, a 3 mg/kg dose of caffeine administered as a capsule significantly improves simple reaction time by 9–11 ms and reduces Stroop interference time by 20–22% during morning and midday sessions, indicating enhanced psychomotor speed and executive control when baseline alertness is suboptimal.

Why this might work

Caffeine blocks natural sleep-promoting signals in the brain, which allows brain chemicals that boost alertness and focus to become more active. This makes the brain process information faster and better ignore distractions, especially when someone is naturally less alert.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Differential Time-of-Day Effects of Caffeine Capsule and Mouth Rinse on Cognitive Performance in Adolescent Male Volleyball Athletes: A Randomized Crossover Investigation

    For young male volleyball players who don’t usually drink caffeine, taking a caffeine pill before morning or midday practice helps them react faster and ignore distractions better — exactly what the study found.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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