Clinical trial NCT03822663: The Influence of Caffeine Supplementation on Specific Performance and Training Activities
Official title: The Influence of Caffeine Supplementation on Discipline-Specific Performance and Training Activities in Combat Sports and Speed-Strength Disciplines
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE3
Conditions: Supplementation
Sports
Keywords: Sports nutrition
Caffeine
Physical capacity
Exercise performance
Lead sponsor: Poznan University of Physical Education
Sponsor class: OTHER
Collaborators: name: Poznan University of Life Sciences
First posted: 2019-01-30
Enrollment: 26
Sex: ALL
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to verify the effect of acute caffeine (CAF) and placebo (PLA) supplementation on physical capacity and discipline-specific exercise performance in athletes, in a randomised, double-blind, placebo-controlled crossover trial.

Detailed description: Caffeine (CAF) is often proposed as an ergogenic agent, especially during high-intensity efforts. CAF supplementation may reduce effort-induced multi-faceted symptoms of fatigue and can improve psychomotor functions (like agility or decision-making processes), which is required during the intermittent high-intensity efforts in combat sports and speed-strength disciplines. Moreover, it is suggested that CAF treatment is associated with increased glycolytic activity during simulated or real training/competition bouts, which results in performance and physical capacity improvement.

However, there are hardly any data on the individual CAF-induced and dose-dependent changes in physical capacity and discipline-specific performance in combat sports and speed-strength disciplines. Therefore, the study aims to examine the effect of acute, different-dose CAF ingestion on physical capacity and discipline-specific performance in combat sports and speed-strength athletes, in a randomized, double-blind, placebo-controlled crossover trial.

Eligibility criteria: Inclusion Criteria:

* written consent to participate,
* a current medical clearance to practice sports,
* training experience: at least 2 years,
* minimum of 4 workout sessions (in the discipline covered by the study) a week.

Exclusion Criteria:

* current injury,
* any health-related contraindication,
* declared general feeling of being unwell,
* unwilling to follow the study protocol.

Primary outcomes:
measure: Changes in discipline-specific exercise capacity after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in caffeine and paraxanthine concencentrations in serum and saliva before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in reaction and motor time (Vienna Test System) after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in postural stability indices (COP velocity, Vcop) (posturographic platform AccuGaitTM) (after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in postural stability indices (area 95 percentile, Area95) (posturographic platform AccuGaitTM) after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
Secondary outcomes:
measure: Changes in sports training / competition activities after discipline-specific exercise tests
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in rate of perceived exertion after discipline-specific exercise tests
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in heart rate during discipline-specific exercise tests
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Analysis of psychological state before and after caffeine supplementation and placebo
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Analysis of macronutrients in diets before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Analysis of body composition (fat-free mass, fat mass)
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Analysis of body composition (total body water)
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in lactate and pyruvate concentrations in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Analysis of gene polymorphisms
timeFrame: Baseline
Other outcomes:
measure: Changes in white blood cells and hematological indices (red blood cells, RBC) count in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (hemoglobin concentration, HGB) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (hematocrit, HCT) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (mean corpuscular volume, MCV; mean platelet volume, MPV) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (mean corpuscular hemoglobin mass, MCH) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (mean corpuscular hemoglobin concentration, MCHC) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (platelet count, PLT) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (platelet hematocrit, PCT) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (platelet distribution width, PDW; platelet large cell ratio, PLCR; red blood cells distribution width - coefficient of variation, RDW-C) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in hematological indices (red blood cells distribution width - standard deviation, RDW-S) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in nutritional status indices (concentration of urea and magnesium) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in nutritional status indices (concentration of glucose, calcium and phosphorans) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in muscle damage markers (concentration of creatine) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
measure: Changes in muscle damage markers (activity of alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase)) in capillary blood before and after caffeine supplementation and placebo treatment
timeFrame: Baseline and during 1 day of acute CAF and PLA supplementation
Locations:
city: Poznań
country: Poland
facility: Department of Sports Dietetics, Poznan University of Physical Education
state: Wielkopolska
Study officials:
affiliation: Department of Sports Dietetics, Poznan University of Physical Education, Poznan, Poland
name: Krzysztof Durkalec-Michalski, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Durkalec-Michalski K, Nowaczyk PM, Glowka N, Grygiel A. Dose-dependent effect of caffeine supplementation on judo-specific performance and training activity: a randomized placebo-controlled crossover trial. J Int Soc Sports Nutr. 2019 Sep 5;16(1):38. doi: 10.1186/s12970-019-0305-8.