The Claim

Caffeine capsule ingestion results in a small but statistically significant increase in lower-limb power output during squat jump and countermovement jump tasks at midday in adolescent male volleyball players compared to caffeine mouth rinsing, indicating that systemic absorption enhances explosive force production beyond orosensory stimulation.

Source: Differential Time-of-Day Effects of Caffeine Capsule and Mouth Rinse on Physical Performance and Volleyball-Specific Skills in Adolescent Male Volleyball Players

What the research says

Supports is higher

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

Supports
70score
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 tested at midday, taking caffeine in capsule form leads to a small but measurable increase in explosive leg power during squat jumps and countermovement jumps compared to rinsing the mouth with caffeine solution.

See the scientific wording

Caffeine capsule ingestion produces a small but statistically significant advantage over mouth rinsing for lower-limb power outputs—specifically squat jump and countermovement jump—at midday in adolescent male volleyball players, suggesting systemic absorption may enhance explosive force production beyond orosensory stimulation.

Why this might work

Caffeine enters the bloodstream after being swallowed, travels to the brain, blocks signals that make the brain feel tired, and makes the brain send stronger signals to the muscles, which makes the legs push harder and faster during jumps.

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 Physical Performance and Volleyball-Specific Skills in Adolescent Male Volleyball Players

    When young male volleyball players swallowed caffeine pills, they jumped slightly higher than when they just swished caffeine in their mouths—suggesting the caffeine entering their bloodstream helps more than just the taste alone.

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

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