SupplementationPhase 3NCT03822663
The Influence of Caffeine Supplementation on Specific Performance and Training Activities
A Phase 3 study testing Caffeine supplementation in people with Supplementation and Sports, run by Poznan University of Physical Education at 1 site in Poland.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Supplementation, Sports
- What is being tested?
- Caffeine supplementation
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 26 participants
- Where
- 1 sitePoland
- Study dates
- 15 May 2017to 20 Dec 2023
- Phase
- Phase 3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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.
Who cannot join
- current injury,
- any health-related contraindication,
- declared general feeling of being unwell,
- unwilling to follow the study protocol.
Trial locations and contacts
1 site in 1 country.
Poland1 site
Department of Sports Dietetics, Poznan University of Physical Education
Poznan, Wielkopolska, 61-871
About this study
Official title: 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.
Read the 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.
- Conditions
- Supplementation, Sports
- Being tested
- Caffeine supplementation, Placebo treatment
- Keywords
- Sports nutrition, Caffeine, Physical capacity, Exercise performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Caffeine supplementationDietary supplement
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 treatmentDietary supplement
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.
| Study group | Role | What they receive |
|---|---|---|
| Caffeine supplementation | Experimental | Group taking oral CAF (Caffeine) supplementation in a different-dose crossover regimen. Receives: Dietary Supplement: Caffeine supplementation |
| Placebo treatment | Placebo comparator | Group taking oral supplementation with placebo. Receives: Dietary Supplement: Placebo treatment |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 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.
Measured: 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
Measured: 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
Measured: 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
Measured: Baseline and during 1 day of acute CAF and PLA supplementation
Secondary outcomes (9)
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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jan 2019
- Study start15 May 2017
- Primary completion1 Mar 2023
- Study completion20 Dec 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for SupplementationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Lead sponsor
- Poznan University of Physical Education
- Sponsor type
- University, hospital or other
- Collaborators
- Poznan University of Life Sciences
- Responsible party
- Principal investigator, Krzysztof Durkalec-Michalski, Poznan University of Physical Education
- Investigators
- Krzysztof Durkalec-Michalski, PhD, Principal investigator, Department of Sports Dietetics, Poznan University of Physical Education, Poznan, Poland
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03822663
- Sponsor's protocol ID
- ULS00007
- Status last verified
- Apr 2024
- First submitted
- 28 Jan 2019
- Last updated
- 26 Apr 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: 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.
Publications
Glowka N, Podgorski T, Malik J, Nowaczyk PM, Durkalec-Michalski K. Hematological and biochemical responses to three doses of caffeine during the CrossFit(R) workout: a randomized, double-blind, crossover trial. J Int Soc Sports Nutr. 2026 Dec 30;23(1):2740805. doi: 10.1080/15502783.2026.2740805. Epub 2026 Oct 23.
PubMed 42924484Glowka N, Malik J, Aniola J, Zawieja EE, Chmurzynska A, Durkalec-Michalski K. The effect of caffeine dose on caffeine and paraxanthine changes in serum and saliva and CYP1A2 enzyme activity in athletes: a randomized placebo-controlled crossover trial. Nutr Metab (Lond). 2024 Nov 11;21(1):90. doi: 10.1186/s12986-024-00863-3.
PubMed 39529054Durkalec-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.
PubMed 31488190
Study at a glance
From the registry record, last updated by the sponsor on 26 Apr 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Influence of Caffeine Supplementation on Discipline-Specific Performance and Training Activities in Combat Sports and Speed-Strength Disciplines
- ClinicalTrials.gov ID
- NCT03822663
- Acronym / sponsor ID
- ULS00007
- Conditions
- Supplementation, Sports
- Keywords
- Sports nutrition, Caffeine, Physical capacity, Exercise performance
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 26 participants (actual)
- Lead sponsor
- Poznan University of Physical EducationUniversity, hospital or other
- Collaborators
- Poznan University of Life Sciences
- Study start
- 15 May 2017 (actual)
- Primary completion
- 1 Mar 2023 (actual)
- Study completion
- 20 Dec 2023 (actual)
- First posted
- 30 Jan 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Caffeine supplementation | Experimental | Dietary Supplement: Caffeine supplementationGroup taking oral CAF (Caffeine) supplementation in a different-dose crossover regimen. |
| Placebo treatment | Placebo comparator | Dietary Supplement: Placebo treatmentGroup taking oral supplementation with placebo. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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.
Key exclusion criteria (4 listed)
- current injury,
- any health-related contraindication,
- declared general feeling of being unwell,
- unwilling to follow the study protocol.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Caffeine supplementationThe 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. | Dietary supplement | Caffeine supplementation |
| Placebo treatmentThe 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. | Dietary supplement | Placebo treatment |
Primary outcome
Changes in discipline-specific exercise capacity after caffeine supplementation and placebo treatment
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Assessment of the discipline-specific exercise capacity tests carried out at baseline, and after CAF and PLA supplementation
Changes in caffeine and paraxanthine concencentrations in serum and saliva before and after caffeine supplementation and placebo treatment
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
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.
Changes in reaction and motor time (Vienna Test System) after caffeine supplementation and placebo treatment
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
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
Changes in postural stability indices (COP velocity, Vcop) (posturographic platform AccuGaitTM) (after caffeine supplementation and placebo treatment
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
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
Changes in postural stability indices (area 95 percentile, Area95) (posturographic platform AccuGaitTM) after caffeine supplementation and placebo treatment
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
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
9 secondary outcomes
Changes in sports training / competition activities after discipline-specific exercise tests
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Changes in rate of perceived exertion after discipline-specific exercise tests
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Changes in heart rate during discipline-specific exercise tests
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of psychological state before and after caffeine supplementation and placebo
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of macronutrients in diets before and after caffeine supplementation and placebo treatment
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of body composition (fat-free mass, fat mass)
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of body composition (total body water)
Time frame: 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
Time frame: Baseline and during 1 day of acute CAF and PLA supplementation
Analysis of gene polymorphisms
Time frame: Baseline
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Apr 2024.
- Derived from this study: PubMed 42924484Glowka N, Podgorski T, Malik J, Nowaczyk PM, Durkalec-Michalski K. Hematological and biochemical responses to three doses of caffeine during the CrossFit(R) workout: a randomized, double-blind, crossover trial. J Int Soc Sports Nutr. 2026 Dec 30;23(1):2740805. doi: 10.1080/15502783.2026.2740805. Epub 2026 Oct 23.
- Derived from this study: PubMed 39529054Glowka N, Malik J, Aniola J, Zawieja EE, Chmurzynska A, Durkalec-Michalski K. The effect of caffeine dose on caffeine and paraxanthine changes in serum and saliva and CYP1A2 enzyme activity in athletes: a randomized placebo-controlled crossover trial. Nutr Metab (Lond). 2024 Nov 11;21(1):90. doi: 10.1186/s12986-024-00863-3.
- Derived from this study: PubMed 31488190Durkalec-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.
- Individual participant dataSharing planned: Undecided. 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Krzysztof Durkalec-Michalski, PhD principal investigator
Department of Sports Dietetics, Poznan University of Physical Education, Poznan, Poland
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Caffeine supplementation in people with Supplementation and Sports, run by Poznan University of Physical Education at 1 site in Poland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Apr 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Poland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in discipline-specific exercise capacity after caffeine supplementation and placebo treatment (time frame: Baseline and during 1 day of acute CAF and PLA supplementation). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03822663, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Apr 2024.