Beetroot Supplementation and High Intensity Exercise

The Effect of Isotonic Beetroot Supplementation on High-intensity Time-trial Performance

Ingested beetroot contains inorganic nitrate which is later converted to nitric oxide (NO) in the bloodstream. NO is an important signaling molecule with several physiological functions in the body including acting as a vasodilator, expanding arteries and improving blood flow. Beetroot juice contain inorganic nitrate and consumption of beetroot has been shown to improve skeletal muscle contractility and metabolism enhancing high-intensity exercise performance. Isotonic sports drinks contain carbohydrates and sodium, which also improve exercise performance by providing exogenous glucose for energy to the working muscle and central nervous system and enabling faster absorption of fluid into the bloodstream. The ingestion of exogenous nitrate and isotonic-carbohydrate drink are recognized strategies for promoting exercise performance but whether they can be effectively combined has not been shown. This study will compare the salivary nitrite response, muscle oxygenation and time-trial performance after ingestion of two isotonic drinks with high in nitrate or with no nitrate.

Study Overview

• Status: Completed
• Conditions: Exercise Performance
• Intervention / Treatment: Dietary supplement: High nitrate isotonic drink; Dietary supplement: No nitrate isotonic drink

Detailed Description

Ingested beetroot contains inorganic nitrate (NO3-) which is later converted to nitric oxide (NO) in the bloodstream. NO is an important signaling molecule with several physiological functions in the body including acting as a vasodilator, expanding arteries and improving blood flow. These functions mean that beetroot juice has become of strong interest in the field of exercise and is a recommended supplement for athletes to improve performance in recent consensus statements by the International Olympic Committee on dietary supplements. Importantly, the consumption of beetroot has been shown to improve skeletal muscle contractility and metabolism, hence, enhancing high-intensity exercise performance . Isotonic sports drinks contain carbohydrates and sodium, which also improve exercise performance by providing exogenous glucose for energy to the working muscle and central nervous system and enabling faster absorption of fluid into the bloodstream. The ingestion of exogenous nitrate and isotonic-carbohydrate drink are recognized strategies for promoting exercise performance but whether they can be effectively combined has not been shown. This study will compare the salivary nitrite response, muscle oxygenation and time-trial performance after ingestion of two drinks either high in nitrate or with no nitrate. Participants will ingest the two drinks in a randomised, crossover double-blind trial. One hour after drink ingestion they will undertake high intensity intermittent exercise for 30 minutes followed by a 10 km time trial on a cycle ergometer. Time trial will be compared between trials as the main outcome. It is hypothesised that the drink high in nitrate will lead to faster time trial completion.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Stephen F Burns, PhD; Phone Number: +65 67903354; Email: stephen.burns@nie.edu.sg

Study Locations

• Singapore
  • Singapore, Singapore, 637616
    • Human Bioenergetics Laboratory, National Institute of Education, Nanyang Technological University

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age: 21 - 40 years
• Healthy and injury-free (e.g., no cardiovascular disease, diabetes mellitus, orthopaedic impairment that interferes with moderate-to-vigorous exercise)
• Blood pressure < 130/90 mmHg
• Physically active: Engaging in a minimum of 150 minutes of moderate-intensity exercise or 75 minutes of vigorous-intensity physical activity each week.
• Recreational cyclist (Minimum 1 hour cycling per week)
• Body mass index: 18.5-25 kg/m2
• Non-smoker
• Asian ethnicity by self identification

Exclusion Criteria:

• Any allergies to beetroot or isotonic drink.
• Asthma.
• Any report of personal health issues that may compromise the individual's ability to undertake exercise safely.
• Any recent Covid vaccination (within last 2 weeks).

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High nitrate; High nitrate isotonic drink	Dietary supplement: High nitrate isotonic drink; High nitrate (12.9 mmol) drink with carbohydrate and minerals
Active Comparator: No nitrate; No nitrate isotonic drink	Dietary supplement: No nitrate isotonic drink; Carbohydrate and mineral isotonic drink

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
10 km cycling time trial (endurance) performance	Time trial	1 hour after drink ingestion the time taken to complete 10 km on a stationary cycle ergometer will be assessed. Time to complete this is the primary outcome measure .

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Salivary nitrate	Salivary nitrate concentration determined from strips	Four samples over 2 hours
Near infra-red spectroscopy (NIRS)	Tissue saturation index	During cycling ~1 hour

Collaborators and Investigators

• Sponsor: Nanyang Technological University
• Investigators: Principal Investigator: Stephen Burns, PhD, Nanyang Technological University

Study record dates

Study Major Dates

• Study Start (Actual): March 15, 2023
• Primary Completion (Actual): March 14, 2024
• Study Completion (Actual): March 14, 2024

Study Registration Dates

• First Submitted: April 11, 2023
• First Submitted That Met QC Criteria: April 23, 2023
• First Posted (Actual): May 3, 2023

Study Record Updates

• Last Update Posted (Actual): April 9, 2024
• Last Update Submitted That Met QC Criteria: April 7, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: IRB-2022-880

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All published data will be placed into the Data Repository of Nanyang Technological University National Institute of Education for public access upon publication.
• IPD Sharing Time Frame: Upon publication - permanent repository
• IPD Sharing Access Criteria: Public repository - exact web address available upon publication.
• IPD Sharing Supporting Information Type: ANALYTIC_CODE

Drug and device information, study documents

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