The Effect of Beetroot Powder on Exercise Performance in Competitive Swimmers
19. juni 2026 oppdatert av: Aysun Köktürk Bayram, Halic University
Swimming requires high energy in a short time and involves overcoming water resistance. Besides regular training, swimmers use supplements to enhance performance, correct nutrient deficiencies, and speed recovery. The Australian Institute of Sport (AIS) classifies supplements by evidence level, with nitrate in Group A. Nitrate aids vasodilation and muscle performance via conversion to nitric oxide (NO).
About 25% of dietary nitrate converts to nitrite by oral bacteria, then to NO in the stomach-a valuable oxygen-independent pathway. NO improves exercise by enhancing oxygen efficiency, muscle contraction, and affecting type II fibers. Timing, dose, nitrate source, and individual traits influence its effect. Beetroot, rich in nitrate, is practical as juice for storage and consumption.
Beetroot gels and juices raise plasma nitrate 1-3 hours post-consumption, effective during 10-17 minute exercises. Some studies found no improvement in short-distance swimming, but others reported dose-dependent benefits. Meta-analyses recommend 5-14.9 mmol nitrate ≥150 minutes before acute exercise, and 5-9.9 mmol for chronic intake. Highly trained athletes may need ≥6-8 mmol NO₃-.
JECFA and the European Commission set acceptable daily intake (ADI) at 0-3.7 mg/kg body weight nitrate ion, safe for all ages.
No long-term, controlled studies exist on beetroot powder's effect in swimmers. To address this, a randomized, placebo-controlled, triple-blind crossover study was designed to evaluate beetroot powder supplementation's impact on competitive swimmers' performance, potentially contributing valuable knowledge.
Studieoversikt
Status
Fullført
Forhold
Intervensjon / Behandling
Detaljert beskrivelse
- Study Design and Participants: This study employed a randomized, double-blind, placebo-controlled crossover design to investigate the effects of beetroot supplementation. Based on a power analysis conducted with a 5% error level and a statistical power of 0.95, a sample size of 36 participants was determined to be sufficient. The study was conducted over a one-year period at the Galatasaray Swimming Club following approval from the institutional ethics committee, and all participants provided written informed consent. Inclusion criteria required voluntary participation with parental consent, an age range of 18-24 years, participation in a structured training program for at least 18 hours per week, no history of chronic disease, no current use of sports or food supplements/medications, and no adherence to a special diet. Conversely, exclusion criteria included irregular training attendance, the presence of chronic diseases, and a failure to cease the use of food supplements one week prior to the study.
- Product Development and Standardization: Three types of beetroot powder were selected from the Turkish market and analyzed by a laboratory accredited under the TURKAK TS EN ISO/IEC 17025:2017 standard, utilizing the HPLC-DAD method in accordance with NMKL No. 165. Based on these analyses, 1.5 g of beetroot powder, corresponding to a 10 mmol nitrate intervention, was used for product development at the Haliç University Nutrition Principles Laboratory. A base mixture of water, gelatin, pectin, starch, and stevia was heated to 85-90°C for homogenization and cooled to 55-60°C. The intervention product contained 1.5 g of beetroot powder, while the placebo product included food coloring to match the visual characteristics of the intervention. Products were prepared 24 hours before each session, stored in opaque, food-safe packaging at 0-4°C, and coded by an independent researcher using a random number generator to ensure triple-blind conditions.
- Experimental Procedure and Controls: Participants were instructed to maintain their habitual dietary intake throughout the study and were provided with a list of nitrate-rich foods to avoid. To prevent interference with oral nitrate-to-nitrite reduction, participants were strictly instructed to abstain from mouthwash, chewing gum, sweets, stimulants, and alcohol on all intervention days. The study consisted of five visits. Visit 1 involved providing study information and obtaining informed consent, while Visit 2 included baseline anthropometric assessments and randomization. Visit 3 involved data collection, including food record retrieval, a standardized warm-up, a 200-m freestyle performance test, and post-test measurements of blood lactate, heart rate, and fatigue. A two-week washout period was implemented between intervention phases to eliminate potential carry-over effects, followed by Visits 4 and 5, where the crossover intervention was conducted by repeating the established testing protocols with the alternative condition.
- Data Collection: Sociodemographic and lifestyle data, including age, sex, education, nutritional habits, and training characteristics, were recorded. Anthropometric measurements included body composition via bioelectrical impedance analysis, height, BMI, and hand grip strength measured by a digital dynamometer. Performance was assessed through a 200-m maximum-effort freestyle swimming test. Physiological assessments included fingertip blood lactate concentration and heart rate (resting, maximum, and average). Finally, subjective fatigue was evaluated using the Perceived Physical and Cognitive Fatigue Scale and the Visual Analog Scale (VAS).
Studietype
Intervensjonell
Registrering (Faktiske)
21
Fase
- Ikke aktuelt
Kontakter og plasseringer
Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.
Studiesteder
-
-
Kartal
-
Istanbul, Kartal, Tyrkia (Türkiye)
- Kartal Kosuyolu Yuksek Ihtisas EAH
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Deltakelseskriterier
Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.
Kvalifikasjonskriterier
Alder som er kvalifisert for studier
- Voksen
Tar imot friske frivillige
Ja
Beskrivelse
Inclusion Criteria:
- Voluntary participation with parental consent
- Age range: 18-24 years
- Participation in a training program for at least 18 hours per week
- No history of chronic disease
- Not currently using any sports supplements, food supplements, or medications
- Not following a special diet
Exclusion Criteria:
- Irregular training participation
- Presence of chronic diseases
- Failure to cease the use of food supplements one week prior to the study
Studieplan
Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.
Hvordan er studiet utformet?
Designdetaljer
- Primært formål: Støttende omsorg
- Tildeling: Randomisert
- Intervensjonsmodell: Crossover-oppdrag
- Masking: Firemannsrom
Våpen og intervensjoner
Deltakergruppe / Arm |
Intervensjon / Behandling |
|---|---|
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Eksperimentell: Beetroot then Placebo
Participants in this arm will first receive 1,5 grams of beetroot powder contain jelly candy daily for 3 consecutive days.
After a 14-day washout period, they will receive placebo jelly candy daily for 3 consecutive days.
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1.5 g of beetroot powder (equivalent to 10 mmol nitrate) administered as a jelly candy.
Color-matched, nitrate-free jelly candy.
|
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Placebo komparator: Placebo then Beetroot
Participants in this arm will first receive placebo jelly candy daily for 3 consecutive days.
After a 14-day washout period, they will receive 1,5 grams of beetroot powder contain jelly candy daily for 3 consecutive days.
|
1.5 g of beetroot powder (equivalent to 10 mmol nitrate) administered as a jelly candy.
Color-matched, nitrate-free jelly candy.
|
Hva måler studien?
Primære resultatmål
Resultatmål |
Tiltaksbeskrivelse |
Tidsramme |
|---|---|---|
|
Change in 200-meter swim performance time
Tidsramme: On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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The duration (in seconds) required for the participant to complete a 200-meter freestyle swim, measured using a Seiko stopwatch.
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On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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Blood lactate concentration
Tidsramme: Immediately post-exercise on the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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Blood lactate levels (mmol/L) measured from capillary blood samples collected 3 minutes after completion of 200-meter swim test.
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Immediately post-exercise on the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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Sekundære resultatmål
Resultatmål |
Tiltaksbeskrivelse |
Tidsramme |
|---|---|---|
|
Visual Analog Scale (VAS) for Perceived Fatigue
Tidsramme: On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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Participant's self-reported fatigue level assessed using a 10-cm visual analog scale, ranging from 0 (no fatigue) to 10 (extreme fatigue), completed immediately after the swim test.
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On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
|
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Heart Rate Change
Tidsramme: On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
|
Maximum heart rate during the 200m swim, heart rate at 1 minute post-performance, and mean heart rate during the test, recorded using a Polar sports watch with an integrated wrist-based optical heart rate monitor.
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On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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Change in Perceived Physical and Cognitive Fatigue Scale (AFBYÖ) Scores
Tidsramme: On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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The 19-item Perceived Physical and Cognitive Fatigue Scale (PPCFS) is a 5-point Likert-type instrument used to assess athletes' perceived fatigue levels after each training session.
The scale consists of two subscales: the Perceived Physical Fatigue (PPF) subscale, which includes the first 8 items with a total score range of 8 to 40, and the Perceived Cognitive Fatigue (PCF) subscale, which includes the remaining 11 items with a total score range of 11 to 55.
The total score of the scale ranges from 19 to 95, where higher scores in either the subscales or the total score indicate increased levels of physical and cognitive fatigue, respectively.
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On the 3rd day of each 3-day intervention period (after beetroot or placebo supplementation).
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Daily Energy and Nutrient Intake
Tidsramme: Collected during the 24-hour period prior to the 3rd day of each 3-day intervention period (both beetroot or placebo supplementation).
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Dietary intake was monitored through 24-hour dietary records kept by participants for 24 hours prior to each measurement day.
Ingredient quantities for composite dishes were calculated using the "Standard Food Recipes" manual.
Subsequently, total daily energy and nutrient intakes were analyzed and quantified using the Nutrition Information System (BeBİS) software.
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Collected during the 24-hour period prior to the 3rd day of each 3-day intervention period (both beetroot or placebo supplementation).
|
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Studer hoveddatoer
Studiestart (Faktiske)
22. desember 2025
Primær fullføring (Faktiske)
22. mai 2026
Studiet fullført (Faktiske)
1. juni 2026
Datoer for studieregistrering
Først innsendt
16. juni 2026
Først innsendt som oppfylte QC-kriteriene
19. juni 2026
Først lagt ut (Faktiske)
23. juni 2026
Oppdateringer av studieposter
Sist oppdatering lagt ut (Faktiske)
23. juni 2026
Siste oppdatering sendt inn som oppfylte QC-kriteriene
19. juni 2026
Sist bekreftet
1. mai 2025
Mer informasjon
Begreper knyttet til denne studien
Andre studie-ID-numre
- 2025-08/318
Plan for individuelle deltakerdata (IPD)
Planlegger du å dele individuelle deltakerdata (IPD)?
NEI
IPD-planbeskrivelse
Individual participant data (IPD) will not be shared due to concerns regarding participant confidentiality and the small sample size, which may increase the risk of re-identification.
Legemiddel- og utstyrsinformasjon, studiedokumenter
Studerer et amerikansk FDA-regulert medikamentprodukt
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Nei
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