Effects of Polyphenols Supplementation on Cycling Endurance

Study Overview
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Brief Summary
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Endurance performance during high intensive exercises is mainly determined by the capacity of the aerobic metabolism. It generally induces muscle fatigue defined as the reversible decline in skeletal muscle contractile performance. Fatigue is multifactorial and is often associated with many physiological parameters including reduced neural input and disruptive metabolic changes in skeletal muscles such as lactic acidosis and the production of oxidative free radicals. Moreover, it could lead to oxidative stress as a result of an imbalance between reactive oxygen species (ROS) production and intrinsic antioxidant defense. To alleviate oxidative stress, some ergogenic strategies have been tested. Numerous studies have reported that different types of supplementation such as selenium, vitamin E, vitamin C or polyphenols were of interest to protect against these mechanisms. Indeed, although some studies demonstrated no or harmful effects, most studies observed positive effects of antioxidants on oxidative stress or performance. More particularly, polyphenols, have great antioxidant capabilities and protective effects and it increases the synthesis and bioavailability of nitric oxide (NO)which is well known to be the most important mediator of vasodilation. To date, most of the studies exploring the effects of polyphenols on exercise investigated several days or weeks of supplementations on vascular, blood parameters (blood pressure, NO concentration, oxidative stress markers) or endurance performance. Conflicting results are often obtained. Only few studies investigated the effects of a single intake on immediate performance and recovery capacity. Therefore, the present work aimed to study the effects of an acute intake of a specific profile polyphenols from grape and apple on physical performances. More specifically, performance, in the present study, referred to high intensity cycling exercise until exhaustion revealing the capacity to maintain a constant strong effort hereafter named endurance. The hypothesis was that an acute of polyphenols would increase the time to exhaustion during a high intensity cycling exercise.

Official Title
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Effects of Acute Specific Grape and Apple Polyphenols Supplementation on Cycling Endurance Performance

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: Vinitrox polyphenols
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Body mass index lower than 27 and waist size lower than 94 cm physical activity higher than 2 hours a week written informed consent Exclusion Criteria: more than 6 hours training a week, regularly trained in aerobic activities asthmatic, smokers or under medicinal drugs dietary supplement, sports drink, special dietary food or functional food, of any kind, liable or presented as liable to enhance physical performances

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Polyphenols<br>The preceding night and one hour before the endurance test, participants were asked to absorb two capsules of 250 mg of polyphenols (Vinitrox™) | Dietary Supplement: Vinitrox polyphenols<br>* Vinitrox™ (Nexira - France) is a combination of specific profile polyphenols from grape and apple. The main polyphenol classes are proanthocyanidins (as catechins, B2 dimer), phenolic acids (as chlorogenic acids, gallic acids) and anthocyanins (as malvidin-3-glucoside). It was administrated the night and the morning before the endurance test (oral administration)<br>|
| Placebo Comparator: placebo<br>The preceding night and one hour before the endurance test, participants were asked to absorb two capsules of placebo (similar appearance and flavour than active comparator). | Dietary Supplement: Placebo<br>* Made with maltodextrin. It was administrated the night and the morning before the endurance test (oral administration).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to exhaustion | Maximal duration during a cycling aerobic exercise (70% of maximal aerobic power) | The total duration of the aerobic exercise (during the cycling aerobic exercise) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate | Heart rate using a polar belt | Immediately before the endurance test, immediately after the endurance test and continuously recorded during three minutes during the recovery to determine half-recovery time | 
| Gaz exchange | oxygen intake using a portable gaz exchange analyzer | Immediately before the endurance test, immediately after the endurance test and continuously recorded during three minutes during the recovery to determine half-recovery time | 
| blood pressure | blood pressure measured at the arm | Immediately before the endurance test, immediately after the endurance test | 
| Pain sensation | Pain sensation using a visual analog scale | Immediately after the endurance exercise and 48 hours after the endurance test | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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polyphenols, aerobic, cycling, endurance, pain