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Related Experiment Video

Updated: Feb 28, 2026

Author Spotlight: Exploring the Impact of Reduced Resistance Exercise Volume on Metabolic Health

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Published on: December 1, 2023

Comparing Acute Effects of Caffeine Delivery Forms on Cross-Training Performance: A Randomized Placebo-Controlled

Salvador Vargas-Molina^1,2, Diego A Bonilla^2,3, Manuel García-Sillero¹

¹Department of Human Physiology, Physical Education and Sport, Faculty of Medicine, University of Malaga, 29010 Malaga, Spain.

|February 27, 2026

Summary

Different caffeine (CAF) forms did not significantly alter internal load or workout performance in CrossFit participants. However, caffeine mouth rinse (CMR) showed a potential improvement in countermovement jump (CMJ) performance.

Keywords:

chewing gum dietary supplements ergogenic aids high-intensity functional training mouth rinse

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Area of Science:

Exercise Physiology
Sports Science
Nutritional Supplementation

Background:

Caffeine is a widely used ergogenic aid in sports.
Optimal caffeine administration methods for specific training modalities like CrossFit are not well-established.
Investigating different caffeine delivery forms is crucial for athletes.

Purpose of the Study:

To compare the effects of various caffeine administration forms (capsule, chewing gum, mouth rinse) on CrossFit performance.
To evaluate the impact on countermovement jump (CMJ), rate of perceived exertion (RPE), repetitions, and heart rate (HR).
To determine if specific caffeine delivery methods offer superior benefits.

Main Methods:

Randomized, placebo-controlled, crossover study with 14 experienced male CrossFit participants.
Caffeine administered via capsule (CC), chewing gum (CCG), and mouth rinse (CMR) or placebo (PG) 30 minutes pre-workout.
Participants performed the 'Cindy' CrossFit protocol; CMJ measured pre/post, RPE, HR, and repetitions recorded post-workout.
A 7-day washout period between each condition ensured independence of measurements.

Main Results:

No significant differences were observed between caffeine forms for RPE, HRmax, HRmean, or total repetitions.
Caffeine mouth rinse (CMR) demonstrated a potentially meaningful improvement in CMJ performance compared to baseline.
Inferential analysis indicated no significant main effects of caffeine administration method on overall outcomes.

Conclusions:

Caffeine administration forms did not consistently enhance internal load or general performance metrics in CrossFit.
Caffeine mouth rinse (CMR) may offer a specific benefit for explosive power, like CMJ, in trained individuals.
Further research is needed to elucidate the precise mechanisms and optimal use of different caffeine delivery systems.