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Cocoa Flavanols and Exercise Capacity

This study has been completed.
Information provided by (Responsible Party):
Klinik für Kardiologie, Pneumologie und Angiologie, Heinrich-Heine University, Duesseldorf Identifier:
First received: December 13, 2010
Last updated: November 7, 2013
Last verified: November 2013
The purpose of this study is to characterize the potential improvement of cocoa flavanols on exercise capacity in highly trained cyclist. A placebo-controlled double-blinded randomized control study will be performed in 13 highly trained cyclist (crossover design). Participants will perform a baseline exercise testing on an ergometer. They will receive either a flavanol-poor or flavanol rich cocoa drink twice daily for one week before a second and third exercise testing is performed. The order of drinks is randomized and balanced (high-flavanol-->low-flavanol drink or low-flavanol drink-->high-flavanol drink)

Condition Intervention
Exercise Capacity
Other: Cocoa

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: The Impact of Dietary Cocoa Flavanols on Cardio-pulmonary Exercise Capacity in Human.

Resource links provided by NLM:

Further study details as provided by Heinrich-Heine University, Duesseldorf:

Primary Outcome Measures:
  • Cardiopulmonary exercise capacity (time to complete time trail, lactate anaerobic threshold, cardio-pulmonary exercise capacity [ Time Frame: 7 days ]

Secondary Outcome Measures:
  • Endothelial function [ Time Frame: 7 days ]

Enrollment: 13
Study Start Date: November 2010
Study Completion Date: November 2013
Primary Completion Date: October 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Flavanol rich cocoa
(596 mg), dissolved in water, twice daily intervention
Other: Cocoa
dissolved in water twice-daily intervention
Experimental: flavanol poor cocoa drink
( 13mg) dissolved in water, twice daily intervention
Other: Cocoa
dissolved in water twice-daily intervention

Detailed Description:

13 participants (highly-trained cyclist, accustomed to exercise testing on ergometers will be enrolled (VO2max>50 ml/kg, FMD >5%, non-smokers, no medication, no diseases, age 20-36, male).

Baseline Testing:

Participants will perform a baseline testing consisting of an ergometric test with a step-wise increase of workload until exhaustion to determine lactate anaerobic threshold and cardio-pulmonary exercise capacity. Vascular function is monitored by Doppler Ultrasound.

In a second test, participants will perform a time trial (goal: as fast as possible)

Flavanol intervention Participants will twice daily receive either a flavanol-poor cocoa drink (13mg/dl)or a flavanol-rich cocoa drink (596mg/dl) over a period of 7 days. Order is randomized and balanced. Subjects will crossover to the second arm after a washout period of 7 days.

Testing performed on baseline day is repeated after the intake of both drinks

In a subgroup of n=6 participants, we will test whether the blood pressure cuff maneuver used for FMD will itself modify nitrite levels. For this the manuever will be completed 4 times and compared to n=6 untreated controls. in another subgroup 6 participants will receive 4times the maneuver but reperfusion will be limited by means of an ultrasound probe.


Ages Eligible for Study:   20 Years to 36 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • highly trained cyclists (VO2 peak > 50 ml/kg bodyweight)
  • refrain from cocoa ingestion during trial
  • training continued throughout testing
  • > 20 years
  • male

Exclusion Criteria:

  • > 36 years
  • poor endothelial function
  • acute infection
  • any chronic heart or pulmonary disease
  • arrhythmias
  • acute or chronic renal failure
  • smokers
  • cardio-vascular risk factors : diabetes mellitus, hypertension, hyperlipidemia
  • intake of nutrition supplements (l-arginine, creatinine)
  • intake of WADA listed doping substances
  Contacts and Locations
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Please refer to this study by its identifier: NCT01259739

Duesseldorf, NRW, Germany, 40225
Sponsors and Collaborators
Heinrich-Heine University, Duesseldorf
Principal Investigator: Tienush Rassaf, MD, PhD Heinrich Heine University Düsseldorf, NRW, Germany
Study Chair: Malte Kelm, MD, PhD Heinrich Heine University Düsseldorf, NRW, Germany
  More Information

Additional Information:
Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Klinik für Kardiologie, Pneumologie und Angiologie, Tienush Rassaf, MD, PhD, Heinrich-Heine University, Duesseldorf Identifier: NCT01259739     History of Changes
Other Study ID Numbers: Flavanols - Exercise
Study First Received: December 13, 2010
Last Updated: November 7, 2013

Keywords provided by Heinrich-Heine University, Duesseldorf:
trained cyclists
no medications
no diseases
non-smokers processed this record on March 24, 2017