NCT07479875

Caffeine Supplementation and Strength Endurance in Brazilian Jiu-jitsu Athletes

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 15 (actual)
• Sponsor: Federal University of Minas Gerais · Academic / Other
• Sex: Male
• Age: 18 Years – 35 Years
• Healthy volunteers: Accepted

Summary

This study investigated the acute effects of ingesting 400 mg of caffeine administered 30 minutes before Brazilian jiu-jitsu-specific strength endurance tests. Experienced athletes completed two conditions, placebo and caffeine, in a randomized, double-blind, crossover clinical trial. Performance was assessed using the dynamic component of the kimono grip strength test (maximum number of repetitions, MNR) and the isometric component (maximum static lift, MSL), both performed with a gi grip. Rating of perceived exertion, adverse effects, and blinding effectiveness were also evaluated.

Detailed description

Caffeine is a widely used ergogenic aid in combat sports due to its effects on alertness, strength, and muscular endurance. This study evaluated whether an absolute dose of 400 mg of caffeine, ingested 30 minutes before testing, improved performance in Brazilian jiu-jitsu-specific strength endurance tests performed with a gi grip. Fifteen experienced athletes completed two experimental sessions separated by at least seven days in a randomized, double-blind, crossover design. In each session, participants performed three maximal sets of the dynamic component of the kimono grip strength test (maximum number of repetitions, MNR) and three trials of the isometric component (maximum static lift, MSL). Dietary intake was controlled during the 24 hours preceding each session, and athletes were instructed to avoid stimulant substances. Adverse effects were monitored for 24 hours following each session, and blinding effectiveness was assessed using the Bang blinding index. The study also examined interindividual variability in response to caffeine supplementation.

Conditions

• Muscle Strength
• Physical Endurance
• Exercise

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Caffeine	Capsule containing 400 mg of anhydrous caffeine ingested 30 minutes before performance testing.
OTHER	Placebo	Capsule containing 400 mg of cornstarch used as placebo, ingested 30 minutes before performance testing.

Timeline

• Start date: 2025-12-12
• Primary completion: 2026-01-15
• Completion: 2026-01-15
• First posted: 2026-03-18
• Last updated: 2026-03-18

Locations

1 site across 1 country: Brazil