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

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: Completed
• Conditions: Aerial Duel Performance in Soccer Players
• Intervention / Treatment: Dietary supplement: Placebo; Dietary supplement: Rhodiola rosea extract; Dietary supplement: Caffeine

• Study Type: Interventional
• Enrollment (Actual): 96
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Early takeoff impulse (Impulse₀-₂₀₀)	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

Outcome Measure	Measure Description	Time Frame
Heading contact height	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	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	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	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)	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

• Sponsor: Beijing Sport University

Study record dates

Study Major Dates

• Study Start (Actual): October 30, 2025
• Primary Completion (Actual): December 27, 2025
• Study Completion (Actual): January 3, 2026

Study Registration Dates

• First Submitted: March 4, 2026
• First Submitted That Met QC Criteria: March 4, 2026
• First Posted (Actual): March 9, 2026

Study Record Updates

• Last Update Posted (Actual): March 9, 2026
• Last Update Submitted That Met QC Criteria: March 4, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Caffeine; Rhodiola rosea; Combined Supplementation; Countermovement Jump (CMJ); Soccer Performance; Neuromuscular Fatigue; Early Impulse (Impulse₀-₂₀₀); Aerial Duel
• Additional Relevant MeSH Terms: Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Alkaloids; Purinones; Purines; Xanthines; Caffeine
• Other Study ID 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