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Placebo Effect on Cycling Performance: Laboratory Crossover Study

15. září 2026 aktualizováno: Poznan University of Physical Education

The Impact of Expectations on Physical Performance and Psychophysiological Potential: a Randomized, Double-blind, Placebo-controlled Crossover Study on the Placebo Effect in the Context of Caffeine Supplementation

This study aims to determine the impact of the placebo (PLA) effect on physical and cognitive performance in a controlled laboratory setting. The study investigates how expectations and beliefs about substance intake (caffeine vs. placebo) interact with actual consumption to influence performance and physiological stress markers. Healthy adults (n = 80) will participate in four testing sessions using a randomized, double-blind, placebo-controlled crossover design. Physiological stress markers (cortisol and alpha-amylase), heart rate, and performance metrics will be monitored during a standardized cycling exercise protocol. This phase provides the dense mechanistic data required to refine a mathematical model of the placebo effect, offering insights into how individual personality traits and cognitive anchoring influence psychophysiological potential.

Přehled studie

Postavení

Zatím nenabíráme

Podmínky

Intervence / Léčba

Detailní popis

This study employs a randomized, double-blind, placebo-controlled crossover design to conduct a multifactorial analysis of psychophysiological and biomechanical dynamics. Participants (n = 80, aged 20-35 years) will complete four experimental sessions separated by 7-day washout periods, involving caffeine (6 mg/kg) or placebo administration. The laboratory protocol (160 minutes) integrates multiple modalities: (1) cognitive testing (Reaction Time Test and Flanker Test), (2) postural control assessment using the BTrackS Balance Plate, and (3) a standardized cycle ergometer exercise protocol consisting of 15 minutes at the anaerobic threshold followed by a 5-minute self-paced maximal effort trial. Belief manipulation (immediate vs. retrospective reporting) and cognitive anchoring (feedback conditions) are implemented to isolate expectancy-driven effects. Continuous metabolic and cardiorespiratory data collected using the Cosmed K5 system will be synchronized with blood biomarkers (lactate, glucose, caffeine, and paraxanthine) and salivary biomarkers (cortisol, testosterone, and alpha-amylase). Advanced statistical methods, including Functional Data Analysis (FDA) and machine learning, will be used to integrate physiological trajectories with behavioral predictors.

Typ studie

Intervenční

Zápis (Odhadovaný)

80

Fáze

  • Nelze použít

Kontakty a umístění

Tato část poskytuje kontaktní údaje pro ty, kteří studii provádějí, a informace o tom, kde se tato studie provádí.

Studijní kontakt

Studijní místa

  • Polsko
    • Wielkopolska
      • Poznan, Wielkopolska, Polsko
        • Poznań University of Physical Education
        • Kontakt:

Kritéria účasti

Výzkumníci hledají lidi, kteří odpovídají určitému popisu, kterému se říká kritéria způsobilosti. Některé příklady těchto kritérií jsou celkový zdravotní stav osoby nebo předchozí léčba.

Kritéria způsobilosti

Věk způsobilý ke studiu

  • Dospělý

Přijímá zdravé dobrovolníky

Ano

Popis

Inclusion Criteria:

  • Age between 20 and 35 years,
  • Healthy adults,
  • Regular physical activity, but not professional athletes,
  • Normal or corrected-to-normal vision,
  • Habitual caffeine consumption.

Exclusion Criteria:

  • History of neurological, psychiatric, cardiovascular, or metabolic disorders,
  • Current use of medication or supplements affecting the central nervous system,
  • Musculoskeletal injuries that would impair physical performance,
  • No habitual caffeine consumption or severe negative side effects of caffeine,
  • Diagnosed sleep disorders or chronic fatigue,
  • Diagnosed major depressive disorder or other severe psychiatric conditions,
  • Presence of any menstrual disorders,
  • Inability to attend all experimental study visits.

Studijní plán

Tato část poskytuje podrobnosti o studijním plánu, včetně toho, jak je studie navržena a co studie měří.

Jak je studie koncipována?

Detaily designu

  • Primární účel: Základní věda
  • Přidělení: Randomizované
  • Intervenční model: Crossover Assignment
  • Maskování: Čtyřnásobek

Zbraně a zásahy

Skupina účastníků / Arm
Intervence / Léčba
Experimentální: Sequence AABB
Participants follow the sequence: Caffeine, Caffeine, Placebo, Placebo, with a 7-day washout period between sessions.
Lék: Caffeine (6mg/kg)
Anhydrous caffeine administered in an encapsulated form at a dosage of 6 mg per kilogram of body mass, 60 minutes before the exercise protocol.
Jiný: Placebo (Starch capsule)
Corn starch administered in an identical encapsulated form as the active caffeine, 60 minutes prior to the laboratory exercise protocol.
Experimentální: Sequence BBAA
Participants follow the sequence: Placebo, Placebo, Caffeine, Caffeine, with a 7-day washout period between sessions.
Lék: Caffeine (6mg/kg)
Anhydrous caffeine administered in an encapsulated form at a dosage of 6 mg per kilogram of body mass, 60 minutes before the exercise protocol.
Jiný: Placebo (Starch capsule)
Corn starch administered in an identical encapsulated form as the active caffeine, 60 minutes prior to the laboratory exercise protocol.
Experimentální: Sequence ABAB
Participants follow the sequence: Caffeine, Placebo, Caffeine, Placebo, with a 7-day washout period between sessions.
Lék: Caffeine (6mg/kg)
Anhydrous caffeine administered in an encapsulated form at a dosage of 6 mg per kilogram of body mass, 60 minutes before the exercise protocol.
Jiný: Placebo (Starch capsule)
Corn starch administered in an identical encapsulated form as the active caffeine, 60 minutes prior to the laboratory exercise protocol.
Experimentální: Sequence BABA
Participants follow the sequence: Placebo, Caffeine, Placebo, Caffeine, with a 7-day washout period between sessions.
Lék: Caffeine (6mg/kg)
Anhydrous caffeine administered in an encapsulated form at a dosage of 6 mg per kilogram of body mass, 60 minutes before the exercise protocol.
Jiný: Placebo (Starch capsule)
Corn starch administered in an identical encapsulated form as the active caffeine, 60 minutes prior to the laboratory exercise protocol.

Co je měření studie?

Primární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
Physical Work Capacity (total work in J)
Časové okno: Measured during each laboratory exercise protocol (approximately 85-120 minutes).
Total physical work performed, expressed in Joules (J), during the standardized laboratory exercise protocol, including both the Anaerobic Threshold phase and the Self-paced Maximal Time-trial.
Measured during each laboratory exercise protocol (approximately 85-120 minutes).
Postural Control (mm)
Časové okno: Measured continuously during the exercise protocol and at T1 (minute 2), T2 (minute 55), and T3 (minute 125).
Center of Pressure excursions measured using the BTrackS Balance Plate and expressed in millimeters (mm).
Measured continuously during the exercise protocol and at T1 (minute 2), T2 (minute 55), and T3 (minute 125).
Explosive power variables (mm)
Časové okno: Continuous recording throughout the exercise protocol and discrete assessments at T1 (2 minute of protocol), T2 (55 minute of protocol), and T3 (125 minute of protocol).
Explosive lower-limb power expressed in millimeters (mm) - Countermovement Jump - height.
Continuous recording throughout the exercise protocol and discrete assessments at T1 (2 minute of protocol), T2 (55 minute of protocol), and T3 (125 minute of protocol).
Psychomotor Vigilance Test Reaction Time (ms)
Časové okno: Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).
Reaction time during the Psychomotor Vigilance Test expressed in milliseconds (ms).
Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).
Flanker Test Reaction Time (ms)
Časové okno: Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).
Reaction time during the Flanker Test expressed in milliseconds (ms).
Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).

Sekundární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
Exercise Heart Rate (bpm)
Časové okno: Measured continuously during each laboratory exercise protocol (approximately 85-120 minutes).
Heart rate expressed in beats per minute (bpm) recorded continuously throughout the standardized laboratory exercise protocol.
Measured continuously during each laboratory exercise protocol (approximately 85-120 minutes).
Exercise Heart Rate Variability (ms)
Časové okno: Measured continuously during each laboratory exercise protocol (approximately 85-120 minutes).
Heart rate variability expressed in milliseconds (ms) and recorded continuously throughout the standardized laboratory exercise protocol to assess autonomic regulation.
Measured continuously during each laboratory exercise protocol (approximately 85-120 minutes).
Simple Reaction Time (ms)
Časové okno: Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).
Reaction time during the Simple Reaction Time test expressed in milliseconds (ms).
Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).
Heart Rate Recovery (bpm)
Časové okno: Measured continuously during the first 5 minutes immediately following exercise cessation.
Heart rate recorded during the post-exercise recovery period, expressed in beats per minute (bpm).
Measured continuously during the first 5 minutes immediately following exercise cessation.
Rating of Perceived Exertion (Borg Scale, points)
Časové okno: Before and immediately after warm-up, immediately after the Anaerobic Threshold phase, immediately after the Self-paced Maximal Time-trial, and immediately after cooldown during each laboratory study visit.
Perceived exertion will be assessed using the Borg Rating of Perceived Exertion Scale and reported in points (6-20).
Before and immediately after warm-up, immediately after the Anaerobic Threshold phase, immediately after the Self-paced Maximal Time-trial, and immediately after cooldown during each laboratory study visit.
Personality Traits (NEO-FFI, points)
Časové okno: Measured at baseline (first study visit).
Personality traits will be assessed using the NEO Five-Factor Inventory (NEO-FFI). The questionnaire provides scores for five personality domains: Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness. Results will be reported as domain scores in points.
Measured at baseline (first study visit).
Mood State (POMS/BRUMS) (points)
Časové okno: Measured during each laboratory study visit.
Mood state assessed using the Profile of Mood States (POMS/BRUMS), expressed in points.
Measured during each laboratory study visit.
Caffeine Expectancy (Caff-EQ-Brief) (points)
Časové okno: Measured 30 minutes post-ingestion.
Caffeine expectancy assessed using the Caffeine Expectancy Questionnaire-Brief (Caff-EQ-Brief), expressed in points.
Measured 30 minutes post-ingestion.
Urine pH
Časové okno: Measured once prior to the start of each laboratory study visit.
Urine pH measured using a urine strip analyzer.
Measured once prior to the start of each laboratory study visit.
White blood cells count and differential (count/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
White blood cells count and differential (%)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (red blood cells, RBC) (count/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (hemoglobin concentration, HGB) (mmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (hematocrit, HCT) (L/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (mean corpuscular volume, MCV; mean platelet volume, MPV) (fL)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (mean corpuscular hemoglobin mass, MCH) (fmol)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (mean corpuscular hemoglobin concentration, MCHC) (mmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (platelet count, PLT) (count/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (platelet hematocrit, PCT) (cL/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (platelet distribution width, PDW; platelet large cell ratio, PLCR; red blood cells distribution width - coefficient of variation, RDW-C) (%)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Hematological indices (red blood cells distribution width - standard deviation, RDW-S) (fL)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the hematological parameter will be performed from fingertip capillary blood collected before supplementation (baseline), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Urea Concentration (mmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Urea concentration measured from fingertip capillary blood and expressed in mmol/L.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Glucose Concentration (mg/dL)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Glucose concentration measured from fingertip capillary blood and expressed in mg/dL.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Creatinine concentration (μmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Creatinine concentration measured from fingertip capillary blood and expressed in µmol/L.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Muscle damage markers (activity of alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase) (U/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of the muscle damage markers (activity of alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase) (U/L) will be performed from fingertip capillary blood.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Lactate concentration (mmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Blood lactate concentration measured from fingertip capillary blood and expressed in mmol/L.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Electrolites' concentration (Ca, Na, K, Cl) (mmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of electrolites' concentration (Ca, Na, K, Cl) (mmol/L) will be performed from fingertip capillary blood.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Blood pH
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of gasometry markers (blood pH) will be performed from fingertip capillary blood.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Partial Pressure of Carbon Dioxide and Oxygen (pCO2, pO2) (mmHg)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of gasometry markers (pCO2, pO2) (mmHg) will be performed from fingertip capillary blood.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
CAF and PAX concentrations (µmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Assessment of caffeine and paraxanthine concentrations (µmol/L) will be performed from fingertip capillary blood.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before exercise, and 3 minutes post-exercise.
Static weight distribution (mm)
Časové okno: Measured at the start of each study visit.
Static weight distribution expressed in millimeters of Center of Pressure symmetry.
Measured at the start of each study visit.
Analysis of body composition (fat-free mass, fat mass) (kg)
Časové okno: Measured at the start of each study visit.
Assessment of body composition (fat-free mass, fat mass) (kg) will be carried out at the start of each study visit.
Measured at the start of each study visit.
Analysis of body composition (total body water) (L)
Časové okno: Measured at the start of each study visit.
Assessment of body composition (total body water) (L) will be carried out at the start of each study visit.
Measured at the start of each study visit.
Analysis of body composition (total body water) (%)
Časové okno: Measured at the start of each study visit.
Assessment of body composition (total body water) (%) will be carried out at the start of each study visit.
Measured at the start of each study visit.
Autonomic Response during Cognitive Performance (bpm)
Časové okno: Measured at three time points: T1 (pre-ingestion; 2 minute of protocol), T2 (post-ingestion/pre-exercise; 55 minute of protocol), and T3 (post-exercise; 125 minute of protocol).
Heart rate and heart rate variability recording during cognitive testing blocks, expressed in beats per minute (bpm).
Measured at three time points: T1 (pre-ingestion; 2 minute of protocol), T2 (post-ingestion/pre-exercise; 55 minute of protocol), and T3 (post-exercise; 125 minute of protocol).
Anthropometric Indices (kg)
Časové okno: Measured at the start of each study visit.
Body mass in kilograms will be measured at the start of each study visit.
Measured at the start of each study visit.
Anthropometric Indices (metres)
Časové okno: Measured at the start of each study visit.
Height in metres will be measured at the start of each study visit.
Measured at the start of each study visit.
Explosive power variables (ms)
Časové okno: Continuous recording throughout the exercise protocol and discrete assessments at T1 (2 minute of protocol), T2 (55 minute of protocol), and T3 (125 minute of protocol).
Explosive lower-limb power variables expressed in milliseconds (ms) - Countermovement Jump - contact time and flight time.
Continuous recording throughout the exercise protocol and discrete assessments at T1 (2 minute of protocol), T2 (55 minute of protocol), and T3 (125 minute of protocol).
Explosive power variables (W)
Časové okno: Continuous recording throughout the exercise protocol and discrete assessments at T1 (2 minute of protocol), T2 (55 minute of protocol), and T3 (125 minute of protocol).
Explosive lower-limb power expressed in Watts (W) - Countermovement Jump - power.
Continuous recording throughout the exercise protocol and discrete assessments at T1 (2 minute of protocol), T2 (55 minute of protocol), and T3 (125 minute of protocol).
Hydration Status (g/mL)
Časové okno: Once prior to the start of each laboratory study visit.
Assessment of urine specific gravity (g/mL) using a urine strip analyzer.
Once prior to the start of each laboratory study visit.
Flanker Test Accuracy (%)
Časové okno: Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).
Accuracy during the Flanker Test expressed as the percentage of correct responses.
Measured at T1 (pre-ingestion, minute 2 of the protocol), T2 (post-ingestion/pre-exercise, minute 55 of the protocol), and T3 (post-exercise, minute 125 of the protocol).
Heart Rate Variability Recovery (ms)
Časové okno: Measured continuously during the first 5 minutes immediately following exercise cessation.
Heart rate variability expressed in milliseconds (ms) during the post-exercise recovery period.
Measured continuously during the first 5 minutes immediately following exercise cessation.
Caffeine Expectancy Questionnaire Score (points)
Časové okno: Measured 30 minutes post-ingestion.
Caffeine expectancy assessed using the Caffeine Expectancy Questionnaire and expressed in points.
Measured 30 minutes post-ingestion.
Suggestibility (SSS) (points)
Časové okno: Measured during the last study visit.
General suggestibility assessed using the Short Suggestibility Scale (SSS), expressed in points.
Measured during the last study visit.
Intrinsic Motivation (IMI) (points)
Časové okno: Measured after each test block during every laboratory study visit.
Task-specific intrinsic motivation assessed using the Intrinsic Motivation Inventory (IMI), expressed in points.
Measured after each test block during every laboratory study visit.
Sport Motivation (SMS) (points)
Časové okno: Measured during the first study visit.
Sport motivation assessed using the Sport Motivation Scale (SMS), expressed in points.
Measured during the first study visit.
Sleep Quality (LSEQ) (points)
Časové okno: Measured once during each laboratory study visit.
Subjective sleep quality assessed using the Leeds Sleep Evaluation Questionnaire (LSEQ), expressed in points.
Measured once during each laboratory study visit.
Salivary Cortisol Concentration (nmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before warm-up (60 minutes post-ingestion), 3 minutes post-exercise, and 10 minutes post-exercise.
Salivary cortisol concentration expressed in nmol/L.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before warm-up (60 minutes post-ingestion), 3 minutes post-exercise, and 10 minutes post-exercise.
Salivary Testosterone Concentration (pmol/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before warm-up (60 minutes post-ingestion), 3 minutes post-exercise, and 10 minutes post-exercise.
Salivary testosterone concentration expressed in pmol/L.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before warm-up (60 minutes post-ingestion), 3 minutes post-exercise, and 10 minutes post-exercise.
Salivary Alpha-amylase Activity (U/L)
Časové okno: Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before warm-up (60 minutes post-ingestion), 3 minutes post-exercise, and 10 minutes post-exercise.
Salivary alpha-amylase activity expressed in U/L.
Measured at baseline (pre-supplementation), 30 minutes post-ingestion, before warm-up (60 minutes post-ingestion), 3 minutes post-exercise, and 10 minutes post-exercise.

Spolupracovníci a vyšetřovatelé

Zde najdete lidi a organizace zapojené do této studie.

Sponzor

Poznan University of Physical Education

Vyšetřovatelé

  • Vrchní vyšetřovatel: Jakub Malik, PhD, Poznan University of Physical Education, Department of Sports Psychology

Termíny studijních záznamů

Tato data sledují průběh záznamů studie a předkládání souhrnných výsledků na ClinicalTrials.gov. Záznamy ze studií a hlášené výsledky jsou před zveřejněním na veřejné webové stránce přezkoumány Národní lékařskou knihovnou (NLM), aby se ujistily, že splňují specifické standardy kontroly kvality.

Hlavní termíny studia

Začátek studia (Odhadovaný)

1. ledna 2027

Primární dokončení (Odhadovaný)

31. března 2028

Dokončení studie (Odhadovaný)

31. března 2029

Termíny zápisu do studia

První předloženo

21. července 2026

První předloženo, které splnilo kritéria kontroly kvality

31. července 2026

První zveřejněno (Aktuální)

5. srpna 2026

Aktualizace studijních záznamů

Poslední zveřejněná aktualizace (Aktuální)

18. září 2026

Odeslaná poslední aktualizace, která splnila kritéria kontroly kvality

15. září 2026

Naposledy ověřeno

1. července 2026

Více informací

Termíny související s touto studií

Klíčová slova

Další relevantní podmínky MeSH

Další identifikační čísla studie

  • 152-2-26
  • 2025/57/N/NZ4/04470 (Jiné číslo grantu/financování: National Science Centre)

Plán pro data jednotlivých účastníků (IPD)

Plánujete sdílet data jednotlivých účastníků (IPD)?

ANO

Popis plánu IPD

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.

Časový rámec sdílení IPD

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.

Kritéria přístupu pro sdílení IPD

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.

Typ podpůrných informací pro sdílení IPD

  • PROTOKOL STUDY

Informace o lécích a zařízeních, studijní dokumenty

Studuje lékový produkt regulovaný americkým FDA

Ne

Studuje produkt zařízení regulovaný americkým úřadem FDA

Ne

Tyto informace byly beze změn načteny přímo z webu clinicaltrials.gov. Máte-li jakékoli požadavky na změnu, odstranění nebo aktualizaci podrobností studie, kontaktujte prosím register@clinicaltrials.gov. Jakmile bude změna implementována na clinicaltrials.gov, bude automaticky aktualizována i na našem webu .

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