Effects of Beetroot Juice Intake on Performance and Physiological Parameters

Study Overview
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Brief Summary
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This study was a randomized, double-blind, crossover design for 3 weeks. In the first week, a researcher explained all the experimental procedures to the participants. In the following two weeks, the participants attended the Exercise Physiology laboratory to be assessed in 2 rowing ergometer sessions, separated from each other by a washout period of 7 days, under the same environmental conditions. In both strictly identical sessions, the participants randomly ingested beetroot juice (BRJ) or placebo (PL) 3 hours before the start of the tests.

Detailed Description
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Three hours after BRJ or PL intake, the participants began the 2,000-meter rowing ergometer test. Before starting (pretest) and at the end of the tests (posttest), blood oxygen saturation, rating of perceived exertion (RPE), and blood lactate measurements were taken. During the rowing ergometer tests, performance parameters and cardiorespiratory variables were recorded.

Official Title
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Effects of Acute Beetroot Juice Intake on Performance, Maximal Oxygen Uptake, and Ventilatory Efficiency in Well-trained Master Rowers: A Randomized, Double-blinded Crossover Study

Conditions
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Pulmonary Function, Nutrition, Healthy

Intervention / Treatment
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* Dietary Supplement: Beetroot juice ingestion
* Dietary Supplement: Placebo ingestion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: national and/or international level; without cardiovascular, respiratory, metabolic, neurological or orthopedic disorders that may affect the performance of the rowing ergometer test; no consumption of drugs or medicines; no smoking; Informed consent to participate in the study signed by all rowers Exclusion Criteria: Ingestion of nutritional supplements taken in the three months prior to the start of the study; no following the guidelines established by the nutrition professional.

Ages Eligible for Study
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Minimum Age: 30 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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: This study was a randomized, double-blind, crossover design
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Beetroot juice intake<br>Beetroot juice was administered 3 h before the start of the rowing ergometer test since the peak of nitrite in the blood occurs 2-3 h after nitrate ingestion. Beetroot juice was provided in a 140 mL maroon plastic bottle with no label. Participants were provided with a randomized bottle containing 140 mL ( 12.8 mmol,  808 mg of nitrate) of BRJ Beet-It-Pro Elite Shot concentrate (Beet IT; James White Drinks Ltd., Ipswich, UK). | Dietary Supplement: Beetroot juice ingestion<br>* Beetroot juice ingestion was randomly administered 3 h before the start of the test to the participants in two assessment sessions with a one-week washout between both sessions.<br>|
| Placebo Comparator: Placebo intake<br>Placebo was administered 3 h before the start of the rowing ergometer test. Placebo was provided in a 140 mL maroon plastic bottle with no label. Participants were provided with a randomized bottle containing 140 mL. The placebo drink was made by dissolving in 1 liter of water 2g of powdered SUPER BEETROOT (  0.01 mmol, 0.620 mg of nitrate, diet, food, Poland), 100% natural beetroot juice and organic label, and adding lemon juice to imitate the flavor and texture of the beetroot juice drink | Dietary Supplement: Placebo ingestion<br>* Placebo ingestion was randomly administered 3 h before the start of the test to the participants in two assessment sessions with a one-week washout between both sessions.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rowing performance: Time trial | minutes:seconds (mm:ss) | through study completion, an average of 3 weeks | 
| Rowing performance: Mean Power output | Watts | through study completion, an average of 3 weeks | 
| Rowing performance: meter per stroke | Meters | through study completion, an average of 3 weeks | 
| Cardiorespiratory performance: absolute oxygen uptake | V̇O2max (L/min) | through study completion, an average of 3 weeks | 
| Cardiorespiratory performance: relative oxygen uptake | V̇O2max (mL/kg/min) | through study completion, an average of 3 weeks | 
| Cardiorespiratory performance: ventilatory efficiency | slope of Ventilation/Carbon dioxide production | through study completion, an average of 3 weeks | 
| Metabolic performance: lactate | mmol/L | through study completion, an average of 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiorespiratory performance: Maximum heart rate | beats/min | through study completion, an average of 3 weeks | 
| Cardiorespiratory performance: Mean heart rate | beats/min | through study completion, an average of 3 weeks | 
| Saturation | percentage | through study completion, an average of 3 weeks | 
| Cardiorespiratory performance: minute ventilation | minute ventilation in L/min | through study completion, an average of 3 weeks | 
| Scale of Perceived exertion ratio (RPE) | Scale from 0 to 10. 0 = rest; 10 = maximum effort | through study completion, an average of 3 weeks | 
| Rowing performance: strokes | Mean strokes per minute | through study completion, an average of 3 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiorespiratory performance, Time trial performance, Beetroot juice, Master rowers, well-trained