Plain English Summary
Background and study aims
Cocoa flavanols (CF) are a supplement made from cocoa beans. They have several beneficial health effects and can stimulate blood flow to provide the body with sufficient oxygen and nutrients when exercising. After exercise, the body needs to recover. The aim of this study is to find out whether taking this CF supplement can help to improve exercise performance and help recovery from exercise.
Who can participate?
Well-trained male cyclists aged 20 to 35
What does the study involve?
Participants undergo a cycling test on the first occasion. On two separate occasions, participants undergo two 30-min all-out cycling exercises (time trials), 1.5 and 3 hours after taking either CF or a placebo (dummy supplement), with a rest in between. Blood samples are taken at the start of the study and before and after each time trial and tested for several markers.
What are the possible benefits and risks of participating?
The possible benefits include improved performance and recovery from exercise. The study does not involve any risks, as the participants are used to heavy exercise and perform cycling training at least 10 hours per week.
Where is the study run from?
Vrije Universiteit Brussel (Belgium)
When is the study starting and how long is it expected to run for?
March 2015 to July 2015
Who is funding the study?
Vrije Universiteit Brussel (Belgium)
Who is the main contact?
Lieselot Decroix
Trial website
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
CFEX
Study information
Scientific title
Effect of acute cocoa flavanols intake on exercise-induced oxidative stress, inflammation and nitric oxide production in healthy athletes: a randomized controlled trial
Acronym
Study hypothesis
It is hypothesized that cocoa flavanol (CF) intake:
1. Will have little or no effect on indirect markers of NO production and exercise performance in healthy, well-trained, subjects
2. Will decrease exercise-induced oxidative stress and inflammation, leading to an improved recovery
Ethics approval
Medical ethics committee UZ Brussel-VUB, 28/01/2015, ref: B.U.N. 143201523265
Study design
Randomized double-blind interventional placebo-controlled cross-over single-centre study
Primary study design
Interventional
Secondary study design
Randomised cross over trial
Trial setting
Community
Trial type
Other
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Condition
Exercise performance and recovery
Intervention
Participants perform an incremental cycling test on the first occasion. On two separate occasions, subjects perform two 30-min time trials on an indoor cycle-ergometer, interposed by passive rest, 1.5 and 3 hours after drinking a single dose of either:
1. Chocolate drink with high cocoa flavanol content (900 mg flavanols) (brandname: acticoa)
2. Placebo chocolate drink (13 mg flavanols)
The drinks are matched in caffeine, theobromine, calories, carbohydrates, fat and proteins.
Lactate, glucose, heart rate, rating of perceived exertion (RPE) and power output were measured during the time trials. Blood will be drawn at baseline and before and after each time trial and analyzed for several markers.
Intervention type
Supplement
Phase
Drug names
Primary outcome measure
1. Epicatechin serum concentration
2. Trolox equivalent antioxidative capacity (TEAC)
3. Uric acid (UA) plasma concentration
4. Malonaldehyde (MDA) plasma concentration
5. L-arginine/ADMA plasma concentration
6. Citrulline plasma concentration
7. Interleukin (IL)-1 plasma concentration
8. IL-6 plasma concentration
9. Tumor necrosis factor (TNF)-α plasma concentration
Measured at baseline and before and after each time trial (pre-TT1, post-TT1, pre-TT1, post-TT1) by HPLC, ELISA and spectrophotometry of plasma and serum (blood)
Secondary outcome measures
1. Time trial performance; time to complete a certain predefined workload during time trial 1 (90-120 min after cocoa intake) and during time trial 2 (210-240 min after cocoa intake)
2. Physiological parameters during time trial:
2.1. Lactate concentration, glucose concentration and rate of perceived exertion at start, after 10 min, after 20 min and at the end of each time trial
2.2. Heart rate and power output at start, after 5, 10, 15, 20, 25 mintues and at the end of each time trial
Overall trial start date
01/03/2015
Overall trial end date
01/07/2015
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Age: between 20 years and 35 years
2. No severe head injuries in the past
3. No intake of neurological or psychological medication
4. Healthy
5. No hypertension
6. No cardiovascular disease
7. Cycling training of at least 10 hours per week for the last 2 years
Participant type
Healthy volunteer
Age group
Adult
Gender
Male
Target number of participants
15
Participant exclusion criteria
1. Age: younger than 20 years or older than 35 years
2. Severe head injuries in the past
3. Intake of neurological or psychological medication which might alter cognitive function (psychotropic drugs, beta adrenergic blockers, steroids)
4. Hypertension
5. Cardiovascular disease
6. Other diseases which can alter cognitive function (diabetes, depression)
Recruitment start date
15/03/2015
Recruitment end date
01/05/2015
Locations
Countries of recruitment
Belgium
Trial participating centre
Vrije Universiteit Brussel
1050
Belgium
Funders
Funder type
University/education
Funder name
Vrije Universiteit Brussel
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
The data will be presented in a peer-reviewed journal.
IPD sharing plan
The datasets generated during and/or analysed during the current study will be available upon request from Lieselot Decroix.
Intention to publish date
01/12/2016
Participant level data
Available on request
Basic results (scientific)
Publication list