Combined Caffeine and Rhodiola Rosea on Aerial Duel Performance in Soccer

NCT07458594 | Completed

• 1 other identifier: 2025602H
• Study Type: interventional
• Target: 96
• Locations: 1 country
• Sites: 2

Brief Summary

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.

Conditions

Aerial Duel Performance in Soccer Players

Keywords

Caffeine; Rhodiola rosea; Combined Supplementation; Soccer Performance; Neuromuscular Fatigue; Countermovement Jump (CMJ); Early Impulse (Impulse₀-₂₀₀); Aerial Duel

Outcome Measures

Primary Outcomes (1)

• 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 Outcomes (5)

• Heading contact height

  Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.

• Heading Ball Velocity

  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

  Baseline (Pre-test) and 4 weeks (Post-test), including measurements under both non-fatigued and fatigued conditions at each time point.

• Neck Isometric Strength

  Baseline (Pre-test) and 4 weeks (Post-test).

• Rate of Perceived Exertion (RPE)

  Immediately after the fatigue-induction protocol and post-fatigue testing at Baseline and 4 weeks.

Study Arms (4)

Placebo Control Group (CTR)

PLACEBO COMPARATOR

Participants receive empty capsules (containing starch or rice flour) identical to the active supplements for 30 days.

Dietary Supplement: Placebo

Rhodiola Rosea Group (RHO)

EXPERIMENTAL

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

Caffeine Group (CAF)

EXPERIMENTAL

A single dose of 3 mg/kg body mass of anhydrous caffeine administered 30 minutes before exercise testing.

Dietary Supplement: Caffeine

Combined Rhodiola and Caffeine Group (RHO + CAF)

EXPERIMENTAL

Combined daily supplementation of 2.4g Rhodiola rosea for 30 days and a single 3 mg/kg dose of caffeine before testing.

Dietary Supplement: Caffeine; Dietary Supplement: Rhodiola rosea extract

Interventions

Caffeine DIETARY_SUPPLEMENT

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.

Caffeine Group (CAF); Combined Rhodiola and Caffeine Group (RHO + CAF)

Rhodiola rosea extract DIETARY_SUPPLEMENT

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.

Combined Rhodiola and Caffeine Group (RHO + CAF); Rhodiola Rosea Group (RHO)

Placebo DIETARY_SUPPLEMENT

Appearance-matched capsules containing inert ingredients (starch or rice flour).

Placebo Control Group (CTR)

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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).

You may not qualify if:

• 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.

Sponsors & Collaborators

• Beijing Sport University: lead

Study Sites (2)

China Football Institute, Beijing Sport University

Beijing, Beijing Municipality, 100084, China

Location

Beijing Sport University

Beijing, China

Location

MeSH Terms

Interventions

Caffeine

Intervention Hierarchy (Ancestors)

Xanthines; Alkaloids; Heterocyclic Compounds; Purinones; Purines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Participants, outcome assessors, and data analysts are blinded to group allocation. Supplement distribution and group coding are managed by an independent researcher not involved in data collection or statistical analysis. All capsules are identical in appearance to maintain blinding throughout the study period.
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Graduate Student

Model Details: This is a 4-week, randomized, double-blind, placebo-controlled, parallel-group trial with four arms (placebo, Rhodiola rosea, caffeine, and Rhodiola rosea plus caffeine; n=24 per arm). Participants complete identical pre- and post-intervention testing sessions. Rhodiola rosea is administered daily throughout the intervention period, while caffeine is administered acutely prior to the test sessions; matching placebo capsules are used to maintain blinding across all groups.

Study Record Dates

• First Submitted: March 4, 2026
• First Posted: March 9, 2026
• Study Start: October 30, 2025
• Primary Completion: December 27, 2025
• Study Completion: January 3, 2026
• Last Updated: March 9, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

CN (2)