Effects of Polyphenols Supplementation on Cycling Endurance

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Dietary Supplement: Vinitrox polyphenols; Dietary Supplement: Placebo

• Registration Number: NCT03214276
• Lead Sponsor: University of Burgundy

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2012-01-01
• Primary Completion: 2012-06-01
• Study Completion: 2012-07-01
• Status Verified: 2017-07
• Study First Submitted: 2017-07-06
• Study First Submitted QC: 2017-07-07
• Last Update Submitted: 2017-07-07
• Study First Posted: 2017-07-11
• Last Update Posted: 2017-07-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 48

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Polyphenols	Vinitrox polyphenols	The preceding night and one hour before the endurance test, participants were asked to absorb two capsules of 250 mg of polyphenols (Vinitrox™)
placebo	Placebo	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).

Primary Outcome Measures

Name	Time	Method
Time to exhaustion	The total duration of the aerobic exercise (during the cycling aerobic exercise)	Maximal duration during a cycling aerobic exercise (70% of maximal aerobic power)

Secondary Outcome Measures

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