The Influence of Caffeine Supplementation on Specific Performance and Training Activities

The Influence of Caffeine Supplementation on Discipline-Specific Performance and Training Activities in Combat Sports and Speed-Strength Disciplines

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.

Study Overview

• Status: Completed
• Conditions: Supplementation; Sports
• Intervention / Treatment: Dietary supplement: Caffeine supplementation; Dietary supplement: Placebo treatment

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.

• Study Type: Interventional
• Enrollment (Actual): 26
• Phase: Phase 3

Contacts and Locations

Study Locations

• Poland
  • Wielkopolska
    • Poznań, Wielkopolska, Poland, 61-871
      • Department of Sports Dietetics, Poznan University of Physical Education

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Caffeine supplementation; Group taking oral CAF (Caffeine) supplementation in a different-dose crossover regimen.	Dietary supplement: Caffeine supplementation; The experimental procedure for each athlete includes an acute CAF supplementation in a different-dose crossover regimen in order to assess whether the dose affects the actual physical capacity and discipline-specific exercise performance (doses: 3.0-, 6.0- and 9.0 mg/kg of body mass, respectively). CAF (pure pharmaceutical caffeine) will be administered in the dissolved form. On testing days, the supplements will be taken 70 min before physical and exercise capacity test session. Between the CAF and PLA or a PLA and CAF treatments, a minimum 7-day washout period will be introduced.
Placebo Comparator: Placebo treatment; Group taking oral supplementation with placebo.	Dietary supplement: Placebo treatment; The experimental procedure for each athlete will include PLA supplementation. Placebo will be administered in the dissolved form. On testing days, the PLA will be taken 70 min before physical and exercise capacity test session. Between the PLA and CAF or a CAF and PLA treatments, a minimum 7-day washout period will be introduced.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in discipline-specific exercise capacity after caffeine supplementation and placebo treatment	Assessment of the discipline-specific exercise capacity tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in caffeine and paraxanthine concencentrations in serum and saliva before and after caffeine supplementation and placebo treatment	Assessment of the caffeine and paraxanthine concencentrations (μg/mL), and paraxanthine/caffeine ratio in serum and saliva before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation. Additionally CYP1A2 enzyme activity was assessed by the determination of the mean time-corrected PRX/CAF RATIO in saliva.	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in reaction and motor time (Vienna Test System) after caffeine supplementation and placebo treatment	Assessment of the reaction and motor time (Vienna Test System) (ms) before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in postural stability indices (COP velocity, Vcop) (posturographic platform AccuGaitTM) (after caffeine supplementation and placebo treatment	Assessment of the postural stability indices (COP velocity, Vcop) (posturographic platform AccuGaitTM) (cm/s) before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in postural stability indices (area 95 percentile, Area95) (posturographic platform AccuGaitTM) after caffeine supplementation and placebo treatment	Assessment of the postural stability indices (area 95 percentile, Area95) (posturographic platform AccuGaitTM) (cm2) before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in sports training / competition activities after discipline-specific exercise tests	Assessment of the sports training / competition activities after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in rate of perceived exertion after discipline-specific exercise tests	Assessment of the Borg Rating of Perceived Exertion (RPE) scale after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in heart rate during discipline-specific exercise tests	Assessment of the Heart Rate during and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of psychological state before and after caffeine supplementation and placebo	Assessment of psychological state by chosen questionnaires was carried out before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of macronutrients in diets before and after caffeine supplementation and placebo treatment	Assessment of the macronutrients in diets (g) was carried out before the execution of exercise protocols on each research visit	Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of body composition (fat-free mass, fat mass)	Assessment of body composition (fat-free mass, fat mass) (kg) was carried out before the execution of exercise protocols on each research visit	Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of body composition (total body water)	Assessment of body composition (total body water) (%) was carried out before the execution of exercise protocols on each research visit	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in lactate and pyruvate concentrations in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the lactate and pyruvate concentration (mmol/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of gene polymorphisms	Assessment of the chosen gene polymorphisms in saliva carried out at baseline	Baseline

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in white blood cells and hematological indices (red blood cells, RBC) count in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the leukocytes (neutrophils, monocytes, lymphocytes, neutrophils:lymphocytes ratio) and the hematological indices (red blood cells, RBC)(count/L) count in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (hemoglobin concentration, HGB) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (hemoglobin concentration, HGB) (mmol/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (hematocrit, HCT) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (hematocrit, HCT) (L/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (mean corpuscular volume, MCV; mean platelet volume, MPV) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (mean corpuscular volume, MCV; mean platelet volume, MPV) (fL) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (mean corpuscular hemoglobin mass, MCH) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (mean corpuscular hemoglobin mass, MCH) (fmol) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (mean corpuscular hemoglobin concentration, MCHC) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (mean corpuscular hemoglobin concentration, MCHC) (mmol/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (platelet count, PLT) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (platelet count, PLT) (count x 109/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (platelet hematocrit, PCT) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (platelet hematocrit, PCT) (cL/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
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	Assessment of the hematological indices (platelet distribution width, PDW; platelet large cell ratio, PLCR; red blood cells distribution width - coefficient of variation, RDW-C) (%) in in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in hematological indices (red blood cells distribution width - standard deviation, RDW-S) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the hematological indices (red blood cells distribution width - standard deviation, RDW-S) (fL) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in nutritional status indices (concentration of urea and magnesium) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the nutritional status indices (concentration of urea and magnesium) (mmol/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in nutritional status indices (concentration of glucose, calcium and phosphorans) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the nutritional status indices (concentration of glucose, calcium and phosphorans) (mg/dL) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
Changes in muscle damage markers (concentration of creatine) in capillary blood before and after caffeine supplementation and placebo treatment	Assessment of the muscle damage markers (concentration of creatine) (μmol/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation
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	Assessment of the muscle damage markers (activity of alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase) (U/L) in capillary blood before and after discipline-specific exercise tests carried out at baseline, and after CAF and PLA supplementation	Baseline and during 1 day of acute CAF and PLA supplementation

Collaborators and Investigators

• Sponsor: Poznan University of Physical Education
• Collaborators: Poznan University of Life Sciences
• Investigators: Principal Investigator: Krzysztof Durkalec-Michalski, PhD, Department of Sports Dietetics, Poznan University of Physical Education, Poznan, Poland

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2017
• Primary Completion (Actual): March 1, 2023
• Study Completion (Actual): December 20, 2023

Study Registration Dates

• First Submitted: January 28, 2019
• First Submitted That Met QC Criteria: January 28, 2019
• First Posted (Actual): January 30, 2019

Study Record Updates

• Last Update Posted (Actual): April 26, 2024
• Last Update Submitted That Met QC Criteria: April 24, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Keywords: Caffeine; Physical capacity; Sports nutrition; Exercise performance
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Purinergic Antagonists; Purinergic Agents; Phosphodiesterase Inhibitors; Purinergic P1 Receptor Antagonists; Central Nervous System Stimulants; Caffeine
• Other Study ID Numbers: ULS00007

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Shared data will be exclusively related to the level of recorded indicators, without personal data. The data obtained will be attached to scientific publications, depending on the requirements of the journal.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No