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The Effects of Acute Nitrate and Caffeine Co-ingestion on Discipline-Specific Exercise Performance.

6. august 2026 oppdatert av: Poznan University of Physical Education

The Acute Effects of Dietary Nitrate (Beetroot Juice), Caffeine, and Their Combination on Discipline-Specific Exercise Performance, Lactate Kinetics, and Physiological Responses in Trained Functional Fitness Athletes and Elite Junior Swimmers.

The purpose of this study is to investigate the acute, separate, and combined ergogenic effects of dietary nitrate (beetroot juice, BJ) and caffeine (CAF) supplementation on discipline-specific athletic performance. The project employs a double-blind, randomized, placebo-controlled, four-arm crossover design. It evaluates two highly distinct, heterogeneous populations of athletes: (A) adult high-intensity functional training (HIFT/CrossFit/Hyrox) competitors performing the standardized Hyrox Physical Fitness Test (P'F'T), and (B) elite junior competitive swimmers (National Team members) performing a progressive 8 × 100 m swimming test. The study will assess physical performance, lactate kinetics, subjective exertion, biochemical indices, psychological metrics, and gastrointestinal tolerance.

Studieoversikt

Status

Status

Indikerer gjeldende rekrutteringsstatus eller utvidet tilgangsstatus.
Har ikke rekruttert ennå

Forhold

Forhold

Sykdommen, lidelsen, syndromet, sykdommen eller skaden som studeres. På ClinicalTrials.gov kan tilstander også inkludere andre helserelaterte problemer, som levetid, livskvalitet og helserisiko.

Intervensjon / Behandling

Intervensjon / Behandling

En prosess eller handling som er fokus for en klinisk studie. Intervensjoner inkluderer legemidler, medisinsk utstyr, prosedyrer, vaksiner og andre produkter som enten er undersøkende eller allerede er tilgjengelige. Intervensjoner kan også inkludere ikke-invasive tilnærminger, som utdanning eller modifisering av kosthold og trening.

Detaljert beskrivelse

This project addresses a critical gap in sports nutrition literature regarding the potential synergistic, additive, or antagonistic interactions of caffeine (CAF) and dietary nitrate (beetroot juice, BJ) when co-administered. While CAF acts primarily as an adenosine receptor antagonist in the central nervous system to enhance motor unit recruitment and decrease perceived exertion, BJ acts as a physiological precursor to nitric oxide, improving peripheral muscle contractility, mitochondrial efficiency, and muscle perfusion.

To evaluate whether these effects are universal or discipline-specific, the trial employs a two-population cohort design:

  • Cohort A (HIFT/Hyrox): Investigates adult functional fitness athletes (aged 18-45) characterized by concurrent strength and endurance adaptations. They will perform the ecological Hyrox P'F'T.
  • Cohort B (Elite Junior Swimmers): Investigates elite junior national team swimmers (aged 16-19) during their centralized training camp. They will undergo the standardized progressive 8 × 100 m step-test.

Furthermore, this study will analyze whether individual hematological markers (iron status) and biochemical profiles correlate with the magnitude of the ergogenic response to establish prospective predictive biomarkers for customized sports nutrition.

Studietype

Studietype

Beskriver arten av en klinisk studie. Studietyper inkluderer intervensjonsstudier (også kalt kliniske studier), observasjonsstudier (inkludert pasientregistre) og utvidet tilgang.
Intervensjonell

Registrering (Antatt)

Registrering

Antall deltakere i en klinisk studie. Den "forventede" påmeldingen er måltallet for deltakere som forskerne trenger for studien.
112

Fase

Fase

Stadiet av en klinisk studie som studerer et medikament eller biologisk produkt, basert på definisjoner utviklet av U.S. Food and Drug Administration (FDA). Fasen er basert på studiens målsetting, antall deltakere og andre egenskaper. Det er fem faser: Tidlig fase 1 (tidligere oppført som fase 0), fase 1, fase 2, fase 3 og fase 4. Ikke relevant brukes til å beskrive studier uten FDA-definerte faser, inkludert utprøving av enheter eller atferdsintervensjoner.
  • Ikke aktuelt

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiekontakt

Studiekontakt

Navn og kontaktinformasjon for personen som kan svare på påmeldingsspørsmål for en klinisk studie. Hvert sted hvor studien gjennomføres kan også ha en spesifikk kontakt, som kan være bedre i stand til å svare på disse spørsmålene.

Studiesteder

  • Polen
    • Wielkopolska
      • Poznan, Wielkopolska, Polen, 61-871
        • Poznań University of Physical Education
        • Ta kontakt med:

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

Kvalifikasjonskriterier

Nøkkelkravene som personer som ønsker å delta i en klinisk studie må oppfylle eller egenskapene de må ha. Kvalifikasjonskriterier består av både inklusjonskriterier (som kreves for at en person skal delta i studien) og eksklusjonskriterier (som hindrer en person i å delta). Typer kvalifikasjonskriterier inkluderer om en studie godtar friske frivillige, har alders- eller aldersgruppekrav, eller er begrenset av kjønn.

Alder som er kvalifisert for studier

  • Barn
  • Voksen

Tar imot friske frivillige

Ja

Beskrivelse

Inclusion Criteria:

A) Cohort A (HIFT / CrossFit / Hyrox):

  • Aged 18-45 years.
  • Minimum of 2 years of systematic HIFT/CrossFit/Hyrox training experience.
  • Performing >4 training sessions per week.
  • Ability to perform the HYROX Physical Fitness Test (P'F'T) and has participated in at least one official HYROX event.
  • Possession of a valid medical certificate proving eligibility for competitive sports.

B) Cohort B (Competitive Junior Swimmers):

  • Aged 16-19 years.
  • Active member of the Polish Junior National Swimming Team.
  • Minimum of 5 years of competitive swimming experience.
  • Current training volume of at least 8-10 pool training sessions per week.
  • Written informed consent obtained from both the participant and their legal guardian (for minors under 18).

C)Common Criteria for Both Cohorts:

  • No history of cardiovascular, respiratory, metabolic, or musculoskeletal disease contradicting high-intensity exercise or stimulant intake.
  • No known food allergies or adverse reactions to beetroot products or caffeine.
  • No current use of medications that alter nitrate/caffeine metabolism (e.g., proton pump inhibitors, antibiotics, phosphodiesterase inhibitors).
  • History of uneventful habituation to caffeine use during training/competition.
  • Willingness to abstain from dietary supplements, antibacterial mouthwashes, alcohol, and high-nitrate foods for 48 hours prior to each testing session.
  • Good general health and physical well-being.

Exclusion Criteria (Applicable to both cohorts):

  • Occurrence of acute musculoskeletal injury or trauma during the study period.
  • Any medical or health contraindications (including severe menstrual disorders, planned pregnancy, or breastfeeding).
  • Failure or refusal to strictly adhere to the dietary, supplementation, and exercise testing protocols.

Studieplan

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Designdetaljer

  • Primært formål: Grunnvitenskap
  • Tildeling: Randomisert
  • Intervensjonsmodell: Crossover-oppdrag
  • Masking: Firemannsrom

Våpen og intervensjoner

Deltakergruppe / Arm

Deltakergruppe / Arm

En gruppe eller undergruppe av deltakere i en klinisk studie som mottar en spesifikk intervensjon/behandling, eller ingen intervensjon, i henhold til studiens protokoll.
Intervensjon / Behandling

Intervensjon / Behandling

En prosess eller handling som er fokus for en klinisk studie. Intervensjoner inkluderer legemidler, medisinsk utstyr, prosedyrer, vaksiner og andre produkter som enten er undersøkende eller allerede er tilgjengelige. Intervensjoner kan også inkludere ikke-invasive tilnærminger, som utdanning eller modifisering av kosthold og trening.
Eksperimentell: CAF + BJ (Active Co-ingestion)
Participants ingest a concentrated beetroot juice shot (~6.4 mmol / 400 mg nitrates) 3 hours before exercise, and a capsule of caffeine (Cohort A: 6 mg/kg body mass; Cohort B: 3 mg/kg body mass) 60 minutes before exercise.
Kosttilskudd: Caffeine
Anhydrous caffeine administered orally in a hard gelatine capsule. To address the unique physiological profiles of the two cohorts, a highly specific, differentiated dosing protocol is implemented: Cohort A (adult functional fitness athletes) will receive a high-performance dose of 6 mg/kg body mass, while Cohort B (elite junior swimmers) will receive a safe, youth-adapted dose of 3 mg/kg body mass. In all experimental trials, the capsule is ingested exactly 60 minutes prior to the onset of the discipline-specific exercise test to match peak plasma caffeine concentration.
Kosttilskudd: Dietary Nitrate (Beetroot Juice)
Concentrated beetroot juice (BJ) administered as a single, acute organic shot of 70 mL (Beet It Sport, James White Drinks Ltd., Ipswich, UK). Each active shot contains approximately 400 mg (equivalent to ~6.4 mmol) of inorganic nitrate. In contrast to chronic loading designs, this study evaluates purely acute effects; the shot is ingested exactly 3 hours (180 minutes) prior to the physical performance test to align with peak systemic concentration of plasma nitrite.
Aktiv komparator: CAF + PLBJ (Caffeine + Placebo BJ)
Participants ingest a nitrate-depleted beetroot juice shot (~0.04 mmol nitrates) 3 hours before exercise, and a capsule of caffeine (Cohort A: 6 mg/kg body mass; Cohort B: 3 mg/kg body mass) 60 minutes before exercise.
Kosttilskudd: Caffeine
Anhydrous caffeine administered orally in a hard gelatine capsule. To address the unique physiological profiles of the two cohorts, a highly specific, differentiated dosing protocol is implemented: Cohort A (adult functional fitness athletes) will receive a high-performance dose of 6 mg/kg body mass, while Cohort B (elite junior swimmers) will receive a safe, youth-adapted dose of 3 mg/kg body mass. In all experimental trials, the capsule is ingested exactly 60 minutes prior to the onset of the discipline-specific exercise test to match peak plasma caffeine concentration.
Kosttilskudd: Placebo (Nitrate-Depleted Beetroot Juice)
Nitrate-depleted beetroot juice (Beet It, James White Drinks Ltd., Ipswich, UK) administered as a 70 mL shot. This placebo is identical in taste, smell, appearance, packaging, and viscosity to the active concentrated shot, but has been selectively filtered to contain negligible nitrate levels (<0.4 mmol / ~25 mg of nitrates). It is ingested exactly 3 hours prior to the exercise test.
Aktiv komparator: PLCAF + BJ (Placebo CAF + Beetroot Juice)
Participants ingest a concentrated beetroot juice shot (~6.4 mmol / 400 mg nitrates) 3 hours before exercise, and a placebo capsule (maltodextrin) 60 minutes before exercise.
Kosttilskudd: Dietary Nitrate (Beetroot Juice)
Concentrated beetroot juice (BJ) administered as a single, acute organic shot of 70 mL (Beet It Sport, James White Drinks Ltd., Ipswich, UK). Each active shot contains approximately 400 mg (equivalent to ~6.4 mmol) of inorganic nitrate. In contrast to chronic loading designs, this study evaluates purely acute effects; the shot is ingested exactly 3 hours (180 minutes) prior to the physical performance test to align with peak systemic concentration of plasma nitrite.
Kosttilskudd: Placebo (Maltodextrin Capsule)
Placebo capsule containing inert maltodextrin powder. The capsule is identical in size, shape, weight, color (opaque), and texture to the active caffeine capsule to ensure robust blinding. It is administered at the exact same time point (60 minutes pre-exercise) according to the identical body-mass-adjusted dosing scheme (simulating either 3 mg/kg or 6 mg/kg).
Placebo komparator: PLCAF + PLBJ (Double Placebo Control)
Participants ingest a nitrate-depleted beetroot juice shot (~0.04 mmol nitrates) 3 hours before exercise, and a placebo capsule (maltodextrin) 60 minutes before exercise.
Kosttilskudd: Placebo (Nitrate-Depleted Beetroot Juice)
Nitrate-depleted beetroot juice (Beet It, James White Drinks Ltd., Ipswich, UK) administered as a 70 mL shot. This placebo is identical in taste, smell, appearance, packaging, and viscosity to the active concentrated shot, but has been selectively filtered to contain negligible nitrate levels (<0.4 mmol / ~25 mg of nitrates). It is ingested exactly 3 hours prior to the exercise test.
Kosttilskudd: Placebo (Maltodextrin Capsule)
Placebo capsule containing inert maltodextrin powder. The capsule is identical in size, shape, weight, color (opaque), and texture to the active caffeine capsule to ensure robust blinding. It is administered at the exact same time point (60 minutes pre-exercise) according to the identical body-mass-adjusted dosing scheme (simulating either 3 mg/kg or 6 mg/kg).

Hva måler studien?

Primære resultatmål

Primære resultatmål

I en klinisk studies protokoll er det planlagte utfallsmålet som er det viktigste for å evaluere effekten av en intervensjon/behandling. De fleste kliniske studier har ett primært utfallsmål, men noen har mer enn ett.
Resultatmål
Tiltaksbeskrivelse
Tidsramme
Exercise Performance Time (minutes and seconds, Cohort A - Hyrox P'F'T)
Tidsramme: At each experimental visit (Visits T1-T4), with visits conducted at 7-day intervals following the baseline/familiarization visit (T0).
Total time (in minutes and seconds) required to complete the standardized HYROX Physical Fitness Test (P'F'T) consisting of 6 specific functional exercises.
At each experimental visit (Visits T1-T4), with visits conducted at 7-day intervals following the baseline/familiarization visit (T0).
Swimming Performance (minutes and seconds, Cohort B - 8x100m Step-Test)
Tidsramme: At each experimental visit (Visits T1-T4), with visits conducted at 7-day intervals following the baseline/familiarization visit (T0).
Swimming performance will be assessed using the completion time (seconds and milliseconds) for each 100-m repetition of the standardized 8 × 100-m step test, including the maximal-effort repetition performed during the fifth stage.
At each experimental visit (Visits T1-T4), with visits conducted at 7-day intervals following the baseline/familiarization visit (T0).

Sekundære resultatmål

Sekundære resultatmål

I en klinisk studies protokoll, et planlagt utfallsmål som ikke er like viktig som det primære utfallsmålet for å evaluere effekten av en intervensjon, men som fortsatt er av interesse. De fleste kliniske studier har mer enn ett sekundært utfallsmål.
Resultatmål
Tiltaksbeskrivelse
Tidsramme
Blood Lactate Kinetics (mmol/L)
Tidsramme: Before supplementation (baseline), pre-exercise (3 hours after beetroot juice supplementation and 30 minutes after caffeine supplementation), and 3 and 7 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Blood lactate concentration, including peak concentration, accumulation kinetics, and clearance rate, will be assessed from fingertip capillary blood collected before supplementation (baseline), pre-exercise (3 hours after beetroot juice supplementation and 30 minutes after caffeine supplementation), and post-exercise (3 and 7 minutes after exercise) at each experimental visit.
Before supplementation (baseline), pre-exercise (3 hours after beetroot juice supplementation and 30 minutes after caffeine supplementation), and 3 and 7 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Heart Rate (HR, bpm)
Tidsramme: Continuously monitored during exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Real-time heart rate (beats per minute) will be continuously monitored throughout each exercise test using a telemetry-based heart rate monitoring system.
Continuously monitored during exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Rating of Perceived Exertion (RPE, points)
Tidsramme: Immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Subjective rating of perceived exertion will be assessed using the validated Borg Scale (6-20).
Immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Blood Pressure (mmHg)
Tidsramme: Measured 2.5 hours after beetroot juice supplementation and 30 minutes after caffeine supplementation (pre-exercise) at each experimental visit (Visits T1-T4; 7-day intervals).
Systolic and diastolic blood pressure will be measured using an automated oscillometric blood pressure monitor.
Measured 2.5 hours after beetroot juice supplementation and 30 minutes after caffeine supplementation (pre-exercise) at each experimental visit (Visits T1-T4; 7-day intervals).
Gastrointestinal Tolerance Profile (mVAS, points)
Tidsramme: Measured 30 minutes after supplementation and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Gastrointestinal symptoms will be assessed using the modified Visual Analog Scale (mVAS; 0-10, where 0 = no symptoms and 10 = extremely severe symptoms).
Measured 30 minutes after supplementation and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
White blood cells count and differential (count/L)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
White blood cells count and differential (%)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (red blood cells, RBC) (count/L)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (hemoglobin concentration, HGB) (mmol/L)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (hematocrit, HCT) (L/L)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (mean corpuscular volume, MCV; mean platelet volume, MPV) (fL)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (mean corpuscular hemoglobin mass, MCH) (fmol)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (mean corpuscular hemoglobin concentration, MCHC) (mmol/L)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (platelet count, PLT) (count/L)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (platelet hematocrit, PCT) (cL/L)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (platelet distribution width, PDW; platelet large cell ratio, PLCR; red blood cells distribution width - coefficient of variation, RDW-C) (%)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Hematological indices (red blood cells distribution width - standard deviation, RDW-S) (fL)
Tidsramme: Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline) and 3 minutes after exercise at each experimental visit.
Before supplementation (baseline) and 3 minutes after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Nutritional status indices (concentration of urea) (mmol/L)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Urea concentration will be assessed from fingertip capillary blood collected before supplementation (baseline).
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Creatinine Concentration (μmol/L)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Creatinine concentration will be assessed from fingertip capillary blood collected before supplementation (baseline).
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Muscle Damage Markers (ALT, AST, CK, LDH) (U/L)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), and lactate dehydrogenase (LDH) will be assessed from fingertip capillary blood collected before supplementation (baseline).
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition (fat-free mass, fat mass) (kg)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition will be assessed before supplementation (baseline) using bioelectrical impedance analysis.
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition (fat-free mass, fat mass) (%)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition will be assessed before supplementation (baseline) using bioelectrical impedance analysis.
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition (total body water) (L)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition will be assessed before supplementation (baseline) using bioelectrical impedance analysis.
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition (total body water) (%)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Body composition will be assessed before supplementation (baseline) using bioelectrical impedance analysis.
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Iron Status (Iron, Ferritin, UIBC, TIBC) (μg/dL)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Serum iron concentration, ferritin concentration, unsaturated iron-binding capacity (UIBC), and total iron-binding capacity (TIBC) will be assessed from fingertip capillary blood collected before supplementation (baseline).
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Iron Status (Transferrin Concentration) (g/L)
Tidsramme: Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Serum transferrin concentration will be assessed from fingertip capillary blood collected before supplementation (baseline).
Before supplementation (baseline) at each experimental visit (Visits T1-T4; 7-day intervals).
Sleep Quality (Visual Analog Scale, VAS; points)
Tidsramme: Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Subjective sleep quality will be assessed using a Visual Analog Scale (VAS).
Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Mood (Brunel Mood Scale, BRUMS; points)
Tidsramme: Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Mood state will be assessed using the Brunel Mood Scale (BRUMS).
Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Competitive State Anxiety (Revised Competitive State Anxiety Inventory-2, CSAI-2R; points)
Tidsramme: Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Competitive state anxiety will be assessed using the Revised Competitive State Anxiety Inventory-2 (CSAI-2R).
Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Felt Arousal (Felt Arousal Scale, FAS; points)
Tidsramme: Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Perceived arousal will be assessed using the Felt Arousal Scale (FAS).
Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Feeling Scale (FS; points)
Tidsramme: Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).
Affective valence will be assessed using the Feeling Scale (FS).
Before supplementation (baseline), pre-exercise, and immediately after exercise at each experimental visit (Visits T1-T4; 7-day intervals).

Samarbeidspartnere og etterforskere

Det er her du vil finne personer og organisasjoner som er involvert i denne studien.

Sponsor

Sponsor

Organisasjonen eller personen som initierer studien og som har myndighet og kontroll over studien.
Poznan University of Physical Education

Etterforskere

Etterforskere

En forsker involvert i en klinisk studie. Beslektede termer inkluderer stedets hovedetterforsker, stedsunderetterforsker, studieleder, studieleder og studiehovedetterforsker.
  • Hovedetterforsker: Natalia Główka, PhD, Poznan University of Physical Education, Department of Sports Dietetics

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart (Antatt)

Studiestart

Den faktiske datoen da den første deltakeren ble registrert i en klinisk studie. Den "forventede" studiestartdatoen er datoen som forskerne tror vil være studiestartdatoen.
1. oktober 2026

Primær fullføring (Antatt)

Primær fullføring

Datoen da den siste deltakeren i en klinisk studie ble undersøkt eller mottok en intervensjon for å samle inn endelige data for det primære utfallsmålet. Hvorvidt den kliniske studien ble avsluttet i henhold til protokollen eller ble avsluttet, påvirker ikke denne datoen. For kliniske studier med mer enn ett primært utfallsmål med ulike fullføringsdatoer, refererer dette begrepet til datoen da datainnsamlingen er fullført for alle de primære utfallsmålene. Den "forventede" primære fullføringsdatoen er datoen som forskerne tror vil være den primære fullføringsdatoen for studien.
30. juni 2029

Studiet fullført (Antatt)

Studiet fullført

Datoen da den siste deltakeren i en klinisk studie ble undersøkt eller mottok en intervensjon/behandling for å samle inn endelige data for de primære utfallsmålene, sekundære utfallsmålene og uønskede hendelsene (det vil si siste deltakers siste besøk). Den "forventede" studiens fullføringsdato er datoen som forskerne tror vil være studiens fullføringsdato.
30. juni 2029

Datoer for studieregistrering

Først innsendt

Først innsendt

Datoen da studiesponsoren eller etterforskeren først sendte inn en studiepost til ClinicalTrials.gov. Det er vanligvis en forsinkelse på noen dager mellom første innsendte dato og postens tilgjengelighet på ClinicalTrials.gov (den første postedatoen).
17. juli 2026

Først innsendt som oppfylte QC-kriteriene

Først innsendt som oppfylte QC-kriteriene

Datoen da studiesponsoren eller etterforskeren først sender inn en studiepost som er i samsvar med gjennomgangskriteriene for National Library of Medicine (NLM) kvalitetskontroll (QC). Sponsoren eller etterforskeren må kanskje revidere og sende inn en studiepost én eller flere ganger før NLMs kvalitetskontrollkriterier oppfylles. Det er sponsorens eller etterforskerens ansvar å sikre at studieposten er i samsvar med NLM QC-gjennomgangskriteriene.
31. juli 2026

Først lagt ut (Faktiske)

Først lagt ut

Datoen da studieposten først var tilgjengelig på ClinicalTrials.gov etter at National Library of Medicine (NLM) kvalitetskontroll (QC) gjennomgang har konkludert. Det er vanligvis en forsinkelse på noen dager mellom datoen studiesponsoren eller etterforskeren sendte inn studieposten og den første postedatoen.
5. august 2026

Oppdateringer av studieposter

Sist oppdatering lagt ut (Faktiske)

Sist oppdatering lagt ut

Den siste datoen da endringer i en studiepost ble gjort tilgjengelig på ClinicalTrials.gov. Det kan være en forsinkelse mellom når endringene ble sendt til ClinicalTrials.gov av studiens sponsor eller etterforsker (datoen for siste innsending av oppdatering) og datoen for siste oppdatering.
7. august 2026

Siste oppdatering sendt inn som oppfylte QC-kriteriene

Siste oppdatering sendt inn som oppfylte QC-kriteriene

Den siste datoen da studiesponsoren eller etterforskeren sendte inn endringer i en studiepost som er i samsvar med gjennomgangskriteriene for National Library of Medicine (NLM) kvalitetskontroll (QC). Det er sponsorens eller etterforskerens ansvar å sikre at studieposten er i samsvar med NLM QC-gjennomgangskriteriene.
6. august 2026

Sist bekreftet

Sist bekreftet

Den siste datoen da studiesponsoren eller etterforskeren bekreftet at informasjonen om en klinisk studie på ClinicalTrials.gov var nøyaktig og oppdatert. Hvis en studie med rekrutteringsstatus for rekruttering; ikke rekrutterer ennå; eller aktiv, ikke rekruttering har ikke blitt bekreftet de siste 2 årene, studiens rekrutteringsstatus vises som ukjent.
1. juli 2026

Mer informasjon

Begreper knyttet til denne studien

Nøkkelord

Ytterligere relevante MeSH-vilkår

Andre studie-ID-numre

Andre studie-ID-numre

Identifikatorer eller ID-numre andre enn NCT-nummeret som er tildelt en klinisk studie av studiens sponsor, finansierere eller andre. Disse tallene kan inkludere unike identifikatorer fra andre prøveregistre og National Institutes of Health-stipendnumre.
  • ZDS2026_NG_001

Plan for individuelle deltakerdata (IPD)

Planlegger du å dele individuelle deltakerdata (IPD)?

JA

IPD-planbeskrivelse

The study protocol will be published as an open-access article. Upon completion of the study, de-identified individual participant data (IPD) and relevant analytic code will be deposited in an open-access repository such as Zenodo or OSF, following the FAIR principles.

IPD-delingstidsramme

The study protocol will be available upon its publication. The IPD and analytic code will be available starting from the date of the primary study results publication and will remain accessible for at least 5 years.

Tilgangskriterier for IPD-deling

The study protocol will be published as an open-access article. Upon completion of the study, de-identified individual participant data (IPD) and relevant analytic code will be deposited in an open-access repository such as Zenodo or OSF, in accordance with FAIR principles.

IPD-deling Støtteinformasjonstype

  • STUDY_PROTOCOL

Legemiddel- og utstyrsinformasjon, studiedokumenter

Studerer et amerikansk FDA-regulert medikamentprodukt

Nei

Studerer et amerikansk FDA-regulert enhetsprodukt

Nei

Denne informasjonen ble hentet direkte fra nettstedet clinicaltrials.gov uten noen endringer. Hvis du har noen forespørsler om å endre, fjerne eller oppdatere studiedetaljene dine, vennligst kontakt register@clinicaltrials.gov. Så snart en endring er implementert på clinicaltrials.gov, vil denne også bli oppdatert automatisk på nettstedet vårt. .

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