Effects of Isotonic Beetroot Supplementation on Sprint Interval Exercise Performance

NCT ID: NCT06349018

Last Updated: 2025-04-13

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 24 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-02-20
• Study Completion Date: 2024-05-31

Brief Summary

This study aims to examine the effects of dietary nitrate supplementation via beetroot juice on sprint interval cycling exercise performance. Twenty-four participants (male or female) will undertake a randomized, crossover trial where they consume either (i) an isotonic beetroot juice drink containing nitrate (12.9 mmol) for 5 days or (ii) an isotonic sports drink (no nitrate) for 5 days. On Day 5 of each trial, participants will come to the laboratory and 2 hours after consuming their allocated drink will complete a 6 bouts of sprint interval exercise. Power output during cycling will be measured as the primary outcome measure. Salivary and plasma measures of nitrate and nitrite will be taken over the course of the morning on Day 5. After a 5-day washout period participants will crossover and begin their second trial.

Detailed Description

This study aims to examine the effects of dietary nitrate supplementation via beetroot juice on sprint interval cycling exercise performance. Twenty-four participants (male or female) will undertake a randomized, crossover trial where they consume either (i) an isotonic beetroot juice drink containing nitrate (12.9 mmol) for 5 days or (ii) an isotonic sports drink (no nitrate) for 5 days. Drinks will be equivalent in isotonicity and colored the same so that participants and investigators will be blinded to each trial. Randomization and drink allocation will be completed by a third person not associated with the study team. On Day 5 of each trial, participants will come to the laboratory and 2 hours after consuming their allocated drink will complete a 6 bouts of sprint interval exercise (10 second all-out maximal sprints interspersed with 50 seconds rest). Power output (peak and mean) during cycling sprints will be measured as the primary outcome measure. Salivary measures of nitrate/nitrite will be taken at three time points over the course of the morning on Day 5 - (i) pre-drink consumption; (ii) 2 hours post-drink consumption; and (iii) post-exercise. Plasma measures of nitrate and nitrite will be taken at two time points over the course of the morning on Day 5 - (i) pre-drink consumption; and (ii) 2 hours post-drink consumption. Near infra-red spectroscopy (NIRS) will be used to measure muscle (vastus lateralis) oxygenation during cycling bouts. A Stroop test to measure inhibition (executive function) will be taken pre- and post-exercise. Sensory perception of the drink will be measured immediately post-consumption on Day 5. After a 5-day washout period participants will crossover and begin their second trial.

Conditions

Exercise Performance

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: OTHER
• Blinding Strategy: DOUBLE

Study Groups

High nitrate

High nitrate isotonic drink

Group Type: EXPERIMENTAL

Dietary Supplement: High nitrate isotonic drink

Intervention Type: OTHER

High nitrate (12.9 mmol) drink with carbohydrate and minerals

No nitrate

No nitrate isotonic drink

Group Type: ACTIVE_COMPARATOR

Dietary Supplement: No nitrate isotonic drink

Intervention Type: OTHER

Carbohydrate and mineral isotonic drink

Interventions

Dietary Supplement: High nitrate isotonic drink

High nitrate (12.9 mmol) drink with carbohydrate and minerals

Intervention Type: OTHER

Dietary Supplement: No nitrate isotonic drink

Carbohydrate and mineral isotonic drink

Intervention Type: OTHER

Eligibility Criteria

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
• Be 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

Exclusion Criteria

• Any allergies to beetroot or isotonic drink.
• Asthma
• Any diagnosed form of cardiometabolic disease (heart disease, stroke, peripheral vascular disease, diabetes, metabolic syndrome, high blood pressure).
• Any symptoms contraindicating exercise testing (e.g. chest pains).
• Any balance or dizziness problems.
• Any chronic medical conditions (whether medicated or not).
• Any bone joint problems.
• Any Physician diagnosed contraindications to exercise.
• Any other health problems that may be a cause for concern or contraindication to exercise.
• Any recent Covid vaccination (within last 2 weeks).

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Nanyang Technological University

OTHER

Sponsor Role: lead

Responsible Party

Stephen Burns

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Human Bioenergetics Laboratory, National Institute of Education, Nanyang Technological University

Singapore, , Singapore

Countries

Singapore

Other Identifiers

IRB-2023-972

Identifier Type: -

Identifier Source: org_study_id