Effects of Beetroot Juice Intake on Performance and Physiological Parameters

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

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.

Study Overview

• Status: Completed
• Conditions: Pulmonary Function; Nutrition, Healthy
• Intervention / Treatment: Dietary supplement: Beetroot juice ingestion; Dietary supplement: Placebo ingestion

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Barcelona
    • Sant Boi De Llobregat, Barcelona, Spain, 08830
      • Campus Docent Sant Joan de Déu. Universitat de Barcelona

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. national and/or international level;
2. without cardiovascular, respiratory, metabolic, neurological or orthopedic disorders that may affect the performance of the rowing ergometer test;
3. no consumption of drugs or medicines;
4. no smoking;
5. Informed consent to participate in the study signed by all rowers

Exclusion Criteria:

1. Ingestion of nutritional supplements taken in the three months prior to the start of the study;
2. no following the guidelines established by the nutrition professional.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Beetroot juice intake; 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; 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.
Placebo Comparator: Placebo intake; 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; 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.

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: Campus docent Sant Joan de Déu-Universitat de Barcelona
• Investigators: Principal Investigator: Manuel V Garnacho-Castaño, PhD, Campus docent Sant Joan de Déu-Universitat de Barcelona

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2018
• Primary Completion (Actual): January 31, 2019
• Study Completion (Actual): February 26, 2019

Study Registration Dates

• First Submitted: September 25, 2023
• First Submitted That Met QC Criteria: October 2, 2023
• First Posted (Actual): October 10, 2023

Study Record Updates

• Last Update Posted (Actual): October 10, 2023
• Last Update Submitted That Met QC Criteria: October 7, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Keywords: Beetroot juice; Time trial performance; Cardiorespiratory performance; Master rowers; well-trained
• Other Study ID Numbers: CDSJD

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No