Effects of Beetroot Juice Intake on Performance and Physiological Parameters

Not Applicable

Completed

• Conditions: Pulmonary Function; Nutrition, Healthy
• Interventions: Dietary Supplement: Beetroot juice ingestion; Dietary Supplement: Placebo ingestion

• Registration Number: NCT06073275
• Lead Sponsor: Campus docent Sant Joan de Déu-Universitat de Barcelona

Brief Summary

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

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 Timeline

• Study Start: 2018-11-01
• Primary Completion: 2019-01-31
• Study Completion: 2019-02-26
• Study First Submitted: 2023-09-25
• Status Verified: 2023-10
• Study First Submitted QC: 2023-10-02
• Last Update Submitted: 2023-10-07
• Study First Posted: 2023-10-10
• Last Update Posted: 2023-10-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 10

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Beetroot juice intake	Beetroot juice ingestion	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).
Placebo intake	Placebo ingestion	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

Primary Outcome Measures

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

Secondary Outcome Measures

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

Trial Locations

Locations (1)

Campus Docent Sant Joan de Déu. Universitat de Barcelona; 🇪🇸 Sant Boi De Llobregat, Barcelona, Spain