Exercise Performance, Nitrate Supplementation, Repeated Sprint Performance in Trained Athletes
Conditions
Keywords
Beetroot juice
Brief summary
This randomized, double-blind, placebo-controlled crossover trial aims to evaluate the acute effects of a nitrate-rich beetroot-based beverage on repeated sprint performance in trained athletes. Ten athletes will complete two experimental conditions in randomized order: beetroot beverage (BET) and placebo (PLA), separated by a 7-day washout period. The beetroot beverage consists of 200 mL of a mixture containing beetroot, cocoa, and green tea, providing approximately 6.4 mmol of nitrate. In each condition, participants will perform a Running Anaerobic Sprint Test (RAST), consisting of six maximal 35-meter sprints with 10 seconds of passive recovery between sprints. The primary outcome is mean power output across the six sprints. Secondary outcomes include fatigue index, sprint-by-sprint power output, heart rate, rating of perceived exertion (Borg 6-20 scale), maximal oxygen uptake (VO₂max), and sleep quality assessed using the Insomnia Severity Index (ISI).
Detailed description
This randomized, double-blind, placebo-controlled crossover trial is designed to investigate the acute effects of a nitrate-rich beetroot-based beverage on repeated sprint performance in trained athletes. Ten athletes will participate in two experimental sessions in randomized order: beetroot beverage (BET) and placebo (PLA). Randomization will determine the sequence of beverage administration. Participants and investigators will be blinded to treatment allocation. After beverage ingestion, participants will perform a standardized warm-up followed by the Running Anaerobic Sprint Test (RAST), consisting of six maximal 35-meter sprints with 10 seconds of passive recovery between sprints. Sprint time will be recorded using electronic timing, and power output will be calculated using body mass and sprint time. The primary outcome measure is mean power output across all six sprints. Secondary outcomes include: Fatigue index (percentage decrement across sprints) Individual sprint power (S1-S6) Heart rate response Rating of perceived exertion (Borg 6-20 scale) VO₂max (assessed at baseline) Sleep quality measured using the Insomnia Severity Index (ISI) A linear mixed-effects model will be used to analyze repeated sprint performance, including subject as a random intercept and treatment, sprint, and their interaction as fixed effects. Non-parametric tests will be applied when assumptions of normality are not met. Statistical significance will be set at p ≤ 0.05.
Interventions
DIETARY_SUPPLEMENTBeetroot-based antioxidant beverage
Participants consumed 200 mL of a beetroot-based antioxidant beverage containing beetroot, cocoa, and green tea extract, providing approximately 6.4 mmol of dietary nitrate. The beverage was administered 2-3 hours before performing a Running Anaerobic Sprint Test (RAST). The formulation was designed to deliver nitrate and polyphenols with potential ergogenic and antioxidant effects. A 7-day washout period separated crossover conditions.
Sponsors
Universidad Autonoma de Chihuahua
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
The study was conducted under a double-blind design. Both participants and investigators were unaware of the beverage allocation (beetroot-based beverage or placebo). The beverages were matched in volume (200 mL), color, taste, and texture. Allocation was performed by an independent researcher not involved in data collection or analysis. Outcome assessors and data analysts were blinded to treatment order until completion of statistical analyses.
Intervention model description
Randomized, double-blind, placebo-controlled crossover design. Participants completed two experimental trials (beetroot-based beverage and placebo) separated by a 7-day washout period. The order of interventions was randomized. Each participant served as his own control. Performance outcomes were assessed using the Running Anaerobic Sprint Test (RAST).
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy trained athletes Age between 18-35 years Regular training ≥3 times/week No cardiovascular or metabolic disease
Exclusion criteria
Healthy trained athletes Age between 18-35 years Regular training ≥3 times/week No cardiovascular or metabolic disease \-
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean power output (W) during six maximal 35-m sprints | Baseline and immediately post-intervention. | Mean power output will be calculated from six maximal 35-m sprint efforts separated by standardized recovery intervals. Sprint time will be recorded and converted to power output (W). The mean value across all six sprints will be used as the outcome measure. |
Contacts
CONTACTEmmanuel Omar Ponce Dávila, MC
Outcome results
None listed