Effects of Acute Beetroot Juice Supplementation on Aerobic Performance, Muscle Oxygenation, and Physiological Responses in Amateur Female Soccer Players
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 13
- Locations
- 1
- Primary Endpoint
- Distance Covered During the 12-Minute Cooper Test
Study Overview
Brief Summary
Effects of Acute Beetroot Juice on Aerobic Performance and Muscle Oxygenation in Amateur Female Soccer Players
Detailed Description
This randomized, double-blind, placebo-controlled crossover study evaluated the acute effects of nitrate-rich beetroot juice supplementation on aerobic performance, muscle oxygenation, and selected physiological responses in amateur female soccer players.
Thirteen participants completed two experimental conditions in randomized order, separated by a 7-day washout period. In one condition, participants consumed 70 mL of nitrate-rich beetroot juice containing 6.4 mmol of nitrate, while in the other condition they consumed an equal volume of low-nitrate blackcurrant placebo containing <0.1 mmol of nitrate. Each beverage was consumed 2.5 hours before exercise testing.
Aerobic performance was assessed using a treadmill-adapted 12-minute Cooper test. Total distance covered and estimated maximal oxygen uptake (VO₂max) were evaluated as performance outcomes. Muscle oxygen saturation was monitored using near-infrared spectroscopy. Heart rate, blood pressure, blood glucose, and rating of perceived exertion were also assessed at predefined time points. Participants and investigators conducting the experimental procedures were blinded to the supplementation condition, and the supplementation sequence was generated by an independent researcher who was not involved in the experimental procedures or statistical analyses.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Other
- Masking
- Double (Participant, Investigator)
Masking Description
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.
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Aged 18 years or older
- •Licensed soccer player for at least 3 years
Exclusion Criteria
- •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
Arms & Interventions
Beetroot Juice, Then Placebo
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.
Intervention: Nitrate-rich beetroot juice (Dietary Supplement)
Beetroot Juice, Then Placebo
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.
Intervention: Low-nitrate blackcurrant placebo beverage (Other)
Placebo,Then Beetroot Juice
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.
Intervention: Nitrate-rich beetroot juice (Dietary Supplement)
Placebo,Then Beetroot Juice
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.
Intervention: Low-nitrate blackcurrant placebo beverage (Other)
Outcomes
Primary Outcomes
Distance Covered During the 12-Minute Cooper Test
Time Frame: During the 12-minute exercise test performed 2.5 hours after supplementation in each crossover condition
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.
Secondary Outcomes
- 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.)
- Rating of Perceived Exertion (RPE)(Baseline and immediately post-exercise in each crossover condition.)
Investigators
Melike Nur Eroğlu
lecturer doctor
Sakarya Applied Sciences University