Clinical trial NCT01259739: Cocoa Flavanols and Exercise Capacity
Official title: The Impact of Dietary Cocoa Flavanols on Cardio-pulmonary Exercise Capacity in Human.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Exercise Capacity
Keywords: trained cyclists
no medications
no diseases
non-smokers
Lead sponsor: Heinrich-Heine University, Duesseldorf
Sponsor class: OTHER
First posted: 2010-12-14
Enrollment: 13
Sex: MALE
Minimum age (years): 20
Maximum age (years): 36
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: 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)

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.

Eligibility criteria: 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

Primary outcomes:
measure: Cardiopulmonary exercise capacity (time to complete time trail, lactate anaerobic threshold, cardio-pulmonary exercise capacity
timeFrame: 7 days
Secondary outcomes:
measure: Endothelial function
timeFrame: 7 days
Other outcomes:
Locations:
city: Duesseldorf
country: Germany
facility: Heinrich-Heine-University
state: NRW
Study officials:
affiliation: Heinrich Heine University Düsseldorf, NRW, Germany
name: Tienush Rassaf, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Heinrich Heine University Düsseldorf, NRW, Germany
name: Malte Kelm, MD, PhD
role: STUDY_CHAIR
References:
citation: Rassaf T, Totzeck M, Hendgen-Cotta UB, Shiva S, Heusch G, Kelm M. Circulating nitrite contributes to cardioprotection by remote ischemic preconditioning. Circ Res. 2014 May 9;114(10):1601-10. doi: 10.1161/CIRCRESAHA.114.303822. Epub 2014 Mar 18.