Ecklonia Cava Supplementation and Cycling Performance

Acute Ecklonia Cava Supplementation Fails to Enhance Performance in Trained Cyclists

The goal of this clinical trial (randomised, double-blind, placebo-controlled crossover study) is to investigate whether supplementation with Ecklonia cava, a natural extract derived from brown seaweed, affects exercise performance and physiological responses in trained cyclists.

The main questions it aims to answer are:

Does Ecklonia cava supplementation improve cycling performance, including power output during steady-state exercise and short maximal sprints? Does Ecklonia cava supplementation influence physiological responses to exercise, such as blood glucose, blood lactate, heart rate, and oxygen consumption?

Researchers will compare Ecklonia cava supplementation to a placebo (a look-alike substance with no active ingredients) to determine whether the supplement has any effect on performance or physiological responses.

In this crossover design, all participants will receive both the Ecklonia cava supplement and the placebo on separate occasions, with a washout period between conditions.

Participants will:

Ingest either Ecklonia cava or a placebo 30 minutes before exercise testing Complete a 60-minute cycling protocol at a moderate intensity Perform repeated short-duration maximal sprint efforts following the steady-state exercise Attend laboratory testing sessions under both supplement and placebo conditions Undergo measurements of physiological responses, including blood glucose, blood lactate, heart rate, oxygen consumption, and respiratory exchange ratio Have exercise performance assessed through measures of power output during cycling

Study Overview

• Status: Completed
• Conditions: Supplementation During Endurance Performance
• Intervention / Treatment: Dietary supplement: Placebo; Dietary supplement: Supplement

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Kingston upon Thames, United Kingdom, KT1 2EE
    • Department of Applied and Human Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• experienced in cycling (defined as completing at least four hours of cycle training per week with a minimum of two years of experience)

Exclusion Criteria:

• Smoker
• cardiovascular disease
• anti-hypertensive medication

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo Supplementation	Dietary supplement: Placebo; Placebo Supplementation
Experimental: Ecklonia Cava Supplementation	Dietary supplement: Supplement; Ecklonia Cava Supplementation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak Power Output During Sprint Performance (Watts)	Peak power output achieved during 20-second maximal sprint efforts performed following a fixed-intensity (55% Wmax) 60-minute cycling protocol	Immediately after the 60-minute submaximal cycling protocol, 30 minutes after supplementation
Mean Power Output During Sprint Performance (Watts)	Mean power output recorded during repeated 20-second maximal sprint efforts following steady-state cycling	Immediately after the 60-minute submaximal cycling protocol, 30 minutes after supplementation
Blood Lactate Concentration During Sprint Cycling (mmol/L)	Blood lactate concentration measured following each repeated sprint efforts (3)	Repeated sprint cycling (3) completed immediately after the 60-minute submaximal cycling protocol, a blood sample taken 2 minutes after each sprint cycling bout. Following each 30-minute supplementation protocol.
Blood Glucose Concentration During Sprint Cycling (mmol/L)	Blood glucose concentration measured following repeated sprint efforts	Repeated sprint cycling (3) completed immediately after the 60-minute submaximal cycling protocol, a blood sample taken 2 minutes after each sprint cycling bout. Following each 30-minute supplementation protocol.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart Rate During Submaximal Cycling (beats per minute)	Average heart rate measured during a 60-minute steady-state cycling protocol performed at 55% maximal power output	During the 60-minute submaximal cycling protocol, 30 minutes after supplementation (each condition)
Blood Lactate Concentration During Submaximal Cycling (mmol/L)	Blood lactate concentration measured during steady-state cycling at 55% maximal power output	Every 20-minutes during the 60-minute submaximal cycling protocol, 30 minutes after supplementation
Blood Glucose Concentration During Submaximal Cycling (mmol/L)	Blood glucose concentration measured during steady-state cycling at 55% maximal power output	Every 20-minutes during the 60-minute submaximal cycling protocol, 30 minutes after supplementation
Oxygen Consumption (VO₂) During Submaximal Cycling (ml/kg/min)	Oxygen consumption measured using indirect calorimetry during steady-state cycling	During the 60-minute submaximal cycling protocol, 30 minutes after supplementation
Respiratory Exchange Ratio (RER) During Submaximal Cycling	Respiratory exchange ratio measured during steady-state cycling using expired gas analysis	During the 60-minute submaximal cycling protocol, 30 minutes after supplementation

Collaborators and Investigators

• Sponsor: University of Exeter
• Collaborators: Kingston University

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2020
• Primary Completion (Actual): September 21, 2020
• Study Completion (Actual): December 2, 2020

Study Registration Dates

• First Submitted: May 5, 2026
• First Submitted That Met QC Criteria: May 20, 2026
• First Posted (Actual): May 28, 2026

Study Record Updates

• Last Update Posted (Actual): May 28, 2026
• Last Update Submitted That Met QC Criteria: May 20, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Dietary Supplements
• Other Study ID Numbers: 1501 (CSL Behring)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Available on request.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

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