Combined Caffeine and Rhodiola Rosea on Aerial Duel Performance in Soccer (CCRP-AD)

March 4, 2026 updated by: Yue Dou, Beijing Sport University

Effects of Combined Caffeine and Rhodiola Rosea Supplementation on Aerial Duel Performance Under Fatigue in Soccer Players

This study will examine whether caffeine (CAF) and Rhodiola rosea (RHO) supplementation, taken alone or in combination, can improve explosive performance and soccer-specific aerial duel performance in trained male soccer players. In a randomized, double-blind, placebo-controlled, parallel design, participants will be assigned to placebo, RHO, CAF, or RHO+CAF for 4 weeks. Performance outcomes will be assessed before and after the intervention using countermovement jump measures (including early take-off impulse) and standardized heading tests (heading reach height, ball exit velocity, and heading duel success rate), with additional measures of neck isometric strength and perceived exertion.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
96

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
      • Beijing, China
        • Beijing Sport University
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100084
        • China Football Institute, Beijing Sport University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Healthy male soccer players from the Beijing Sport University team.

Systematic soccer-specific training background and stable competitive level.

Suitable for high-intensity physical testing based on the Physical Activity Readiness Questionnaire (PAR-Q).

Exclusion Criteria:

  • History of neuromuscular or musculoskeletal system diseases.

Intake of caffeine (coffee/tea), other supplements, ergogenic aids, or alcohol within the last 3 months.

Current use of antidepressants or central nervous system stimulants.

Smokers.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: Placebo Control Group (CTR)
Participants receive empty capsules (containing starch or rice flour) identical to the active supplements for 30 days.
Dietary supplement: Placebo
Appearance-matched capsules containing inert ingredients (starch or rice flour).
Experimental: Rhodiola Rosea Group (RHO)
Daily supplementation of 2.4g Rhodiola rosea extract (approx. 12mg salidroside) for 30 days, taken in two doses before breakfast and lunch.
Dietary supplement: Rhodiola rosea extract
Standardized Rhodiola rosea extract capsules. Daily total dosage of 2.4 g (containing approx. 12 mg salidroside), taken twice daily (before breakfast and lunch) for 30 days.
Experimental: Caffeine Group (CAF)
A single dose of 3 mg/kg body mass of anhydrous caffeine administered 30 minutes before exercise testing.
Dietary supplement: Caffeine
Anhydrous caffeine capsules administered at a dose of 3 mg/kg body weight. Taken as a single dose 30 minutes prior to the physical performance tests.
Experimental: Combined Rhodiola and Caffeine Group (RHO + CAF)
Combined daily supplementation of 2.4g Rhodiola rosea for 30 days and a single 3 mg/kg dose of caffeine before testing.
Dietary supplement: Rhodiola rosea extract
Standardized Rhodiola rosea extract capsules. Daily total dosage of 2.4 g (containing approx. 12 mg salidroside), taken twice daily (before breakfast and lunch) for 30 days.
Dietary supplement: Caffeine
Anhydrous caffeine capsules administered at a dose of 3 mg/kg body weight. Taken as a single dose 30 minutes prior to the physical performance tests.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Early takeoff impulse (Impulse₀-₂₀₀)
Time Frame: Baseline (Day 0) and Post-intervention (Day 30), measured under both non-fatigued and fatigued conditions.
Calculated as the integration of vertical force over the first 200 ms of the countermovement jump (CMJ) takeoff phase, relative to body mass (N·s·kg-¹). This measures the capacity for rapid force production.
Baseline (Day 0) and Post-intervention (Day 30), measured under both non-fatigued and fatigued conditions.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Heading contact height
Time Frame: Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.
Participants perform a header and touch a football suspended on a vertical jump tester with their forehead. The highest touch height from three trials is recorded to reflect aerial reach capacity.
Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.
Heading Ball Velocity
Time Frame: Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.
The maximum velocity of the ball after heading is measured using a speed device. A ball machine is used to ensure consistent delivery direction and speed. This measures momentum transfer efficiency and technical execution.
Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.
Aerial Duel Success Rate
Time Frame: Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.
Calculated as the percentage of successful duels out of a fixed number of trials in a standardized head-to-head setting. Success is defined as effectively contacting the ball first and directing it toward a target area.
Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.
Neck Isometric Strength
Time Frame: Baseline (Pre-test) and 4 weeks (Post-test).
Maximum isometric force measured in neck flexion and extension using a handheld dynamometer. Values are normalized to body mass ($N \cdot kg^{-1}$) to assess the stability of the head-trunk system.
Baseline (Pre-test) and 4 weeks (Post-test).
Rate of Perceived Exertion (RPE)
Time Frame: Immediately after the fatigue-induction protocol and post-fatigue testing at Baseline and 4 weeks.
Subjective effort level reported by participants on a scale of 1 to 10 (1 = nearly no effort, 10 = extreme effort) immediately following the fatigue protocol and post-fatigue tests.
Immediately after the fatigue-induction protocol and post-fatigue testing at Baseline and 4 weeks.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Beijing Sport University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 30, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 27, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 3, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 4, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 4, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 9, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2025602H

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared due to participant confidentiality and institutional data protectionpolicies.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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