Cocoa Flavanols and Exercise Capacity
- Conditions
- Exercise Capacity
- Registration Number
- NCT01259739
- Lead Sponsor
- Heinrich-Heine University, Duesseldorf
- 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.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 13
- highly trained cyclists (VO2 peak > 50 ml/kg bodyweight)
- refrain from cocoa ingestion during trial
- training continued throughout testing
- > 20 years
- male
- > 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
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Primary Outcome Measures
Name Time Method Cardiopulmonary exercise capacity (time to complete time trail, lactate anaerobic threshold, cardio-pulmonary exercise capacity 7 days
- Secondary Outcome Measures
Name Time Method Endothelial function 7 days
Trial Locations
- Locations (1)
Heinrich-Heine-University
🇩🇪Duesseldorf, NRW, Germany
Heinrich-Heine-University🇩🇪Duesseldorf, NRW, Germany