Effects of Acute Beetroot Juice on Aerobic Performance and Muscle Oxygenation in Amateur Female Soccer Players

NCT07840014 | Completed

• 1 other identifier: SUBU-BJ-2025-01
• Study Type: interventional
• Target: 13
• Locations: 1 country
• Sites: 1

Brief Summary

Effects of Acute Beetroot Juice on Aerobic Performance and Muscle Oxygenation in Amateur Female Soccer Players

Conditions

Exercise Physiology; Sports Nutrition; Cardiorespiratory Fitness

Keywords

Beetroot juice; Dietary nitrate; Aerobic performance; Muscle oxygenation; Female soccer players

Outcome Measures

Primary Outcomes (1)

• Distance Covered During the 12-Minute Cooper Test

  Total distance covered, expressed in meters, during a self-paced treadmill-adapted 12-minute Cooper test. Participants were instructed to cover the greatest possible distance within 12 minutes and were allowed to adjust treadmill speed throughout the test.

  During the 12-minute exercise test performed 2.5 hours after supplementation in each crossover condition

Secondary Outcomes (6)

• Estimated Maximal Oxygen Uptake (VO₂max)

  At completion of the 12-minute exercise test performed 2.5 hours after supplementation in each crossover condition.

• Muscle Oxygen Saturation (SmO₂)

  Baseline (2 minutes before warm-up), during the 12-minute exercise test, and early post-exercise (approximately 2-3 minutes after exercise) in each crossover condition.

• Heart Rate

  Pre-exercise, continuously during the 12-minute exercise test, approximately 2-3 minutes post-exercise, and approximately 29-30 minutes post-exercise in each crossover condition.

• Blood Pressure

  Before supplementation, pre-exercise, 3 minutes post-exercise, and 30 minutes post-exercise in each crossover condition.

• Blood Glucose

  Immediately before supplementation, pre-exercise (2 minutes before warm-up), and immediately post-exercise in each crossover condition.

Study Arms (2)

Beetroot Juice, Then Placebo

EXPERIMENTAL

Participants first received 70 mL of nitrate-rich beetroot juice containing 6.4 mmol nitrate. After a 7-day washout period, they received 70 mL of low-nitrate blackcurrant placebo containing \<0.1 mmol nitrate. Each beverage was consumed 2.5 hours before the 12-minute exercise test.

Dietary Supplement: Nitrate-rich beetroot juice; Other: Low-nitrate blackcurrant placebo beverage

Placebo,Then Beetroot Juice

EXPERIMENTAL

Participants first received 70 mL of low-nitrate blackcurrant placebo containing \<0.1 mmol nitrate. After a 7-day washout period, they received 70 mL of nitrate-rich beetroot juice containing 6.4 mmol nitrate. Each beverage was consumed 2.5 hours before the 12-minute exercise test.

Dietary Supplement: Nitrate-rich beetroot juice; Other: Low-nitrate blackcurrant placebo beverage

Interventions

Nitrate-rich beetroot juice DIETARY_SUPPLEMENT

Participants consumed a single 70 mL dose of nitrate-rich beetroot juice (Beet It Pro Elite Shot, James White Drinks Ltd., Ipswich, UK) containing 6.4 mmol (approximately 400 mg) of nitrate. The supplement was ingested 2.5 hours before the 12-minute exercise test.

Beetroot Juice, Then Placebo; Placebo,Then Beetroot Juice

Low-nitrate blackcurrant placebo beverage OTHER

Participants consumed a single 70 mL dose of low-calorie blackcurrant beverage (Pfanner, Austria) containing negligible nitrate (\<0.1 mmol). The placebo was ingested 2.5 hours before the 12-minute exercise test.

Beetroot Juice, Then Placebo; Placebo,Then Beetroot Juice

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Female
• Aged 18 years or older
• Licensed soccer player for at least 3 years

You may not qualify if:

• Use of pharmacological treatment or supplements/ergogenic aids that could affect exercise performance, including stimulants such as caffeine
• Presence of musculoskeletal, ligament, bone, neurological, or joint pathology incompatible with the exercise protocol
• Current cardiovascular problems
• Participation in additional sports or physical activities during the study period that could affect the study outcomes

Sponsors & Collaborators

• Sakarya Applied Sciences University: lead

Study Sites (1)

Sakarya University of Applied Sciences Esentepe Campus Sports Sciences Faculty

Sakarya, Turkey (Türkiye)

Location

Study Officials

• MELIKE N EROGLU

  Sakarya Applied Sciences University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Participants and investigators conducting the experimental procedures were blinded to the supplementation condition. Supplementation order was generated by an independent researcher who was not involved in the experimental procedures or statistical analyses.
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: lecturer doctor

Model Details: Participants completed both intervention conditions in randomized order. Each participant received beetroot juice in one period and placebo in the other, with a 7-day washout period between conditions.

Study Record Dates

• First Submitted: September 15, 2026
• First Posted: September 24, 2026
• Study Start: August 1, 2025
• Primary Completion: September 2, 2025
• Study Completion: September 2, 2025
• Last Updated: September 24, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)