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Placebo Effect in Field-Based Physical Performance

31. července 2026 aktualizováno: Poznan University of Physical Education

Psychophysiological Mechanisms of the Placebo Effect on Physical Performance in Field Settings

This study aims to investigate the placebo (PLA) effect on physical performance across different sports disciplines in real-world, field-based settings. The study investigates how participant expectations and beliefs regarding caffeine (CAF) intake influence physical performance and psychomotor function outside the controlled laboratory environment. Healthy, physically active adults (n = 120) from diverse sports backgrounds will be randomly assigned to receive caffeine, placebo, or no intervention. Participants will perform discipline-specific field exercise tests (e.g., running-based protocols or repeated sprint protocols) while physiological responses are monitored using wearable technology. Physical performance outcomes and psychomotor responses will be analyzed to evaluate the real-world impact of the placebo effect and to distinguish the pharmacological effects of caffeine from those driven by psychological expectations across different athletic settings.

Přehled studie

Postavení

Zatím nenabíráme

Podmínky

Intervence / Léčba

Detailní popis

This study employs a cross-sectional design conducted in diverse field settings to investigate the placebo (PLA) effect across different sports disciplines. Participants (n = 120, aged 20-35 years) representing different training profiles (endurance and mixed) will be randomly assigned to one of three parallel groups: Caffeine, Placebo, or Control. Each participant will complete a single experimental session lasting approximately 35 minutes, consisting of: (1) baseline psychomotor assessment using the Simple Reaction Time test, (2) a discipline-specific exercise protocol (e.g., the Cooper test performed on an athletics track or a Repeated Sprint Ability protocol), and (3) post-exercise recovery monitoring. Physiological parameters, including heart rate (HR), heart rate variability (HRV), and respiratory rate (RR), together with postural stability, will be continuously monitored using wearable technology. The study will evaluate how psychological expectations influence physical performance, psychomotor function, and physiological responses during sport-specific exercise, providing evidence for the role of the placebo effect under real-world athletic conditions.

Typ studie

Intervenční

Zápis (Odhadovaný)

120

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

    • Greater Poland Voivodeship
      • Poznan, Greater Poland Voivodeship, 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,
  • 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: Paralelní přiřazení
  • Maskování: Čtyřnásobek

Zbraně a zásahy

Skupina účastníků / Arm
Intervence / Léčba
Experimentální: Caffeine Group
Participants ingest a single dose of caffeine (6mg/kg body mass) prior to a field-based exercise protocol (e.g., Cooper test or Repeated Sprint Ability).
Anhydrous caffeine administered in an encapsulated form at a dosage of 6mg per kilogram of body mass, 30-60 minutes before the exercise protocol.
Aktivní komparátor: Placebo Group
Participants ingest a single dose of placebo (corn starch) in an identical capsule prior to a field-based exercise protocol.
Corn starch administered in an identical encapsulated form as the active caffeine, 30-60 minutes before the exercise protocol.
Falešný srovnávač: Control Group
Participants perform the same field-based exercise protocol without ingesting any capsule or active substance.
Participants perform the same exercise protocols without any capsule or substance administration.

Co je měření studie?

Primární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
Physical Performance Capacity (total distance in running, metres)
Časové okno: Measured during the exercise protocol immediately following administration of the study intervention.
Total physical work capacity measured as the total running distance (metres) completed during the standardized exercise protocol.
Measured during the exercise protocol immediately following administration of the study intervention.
Physical Performance Capacity (total work in Joules for cycling)
Časové okno: Measured during the exercise protocol immediately following administration of the study intervention.
Total physical work capacity measured as the total mechanical work (Joules) completed during the standardized cycling exercise protocol.
Measured during the exercise protocol immediately following administration of the study intervention.
Physical Performance Capacity (exercise duration until exhaustion, minutes)
Časové okno: Measured during the exercise protocol immediately following administration of the study intervention.
Total physical work capacity measured as exercise duration until volitional exhaustion during the standardized exercise protocol.
Measured during the exercise protocol immediately following administration of the study intervention.

Sekundární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
Exercise Heart Rate (bpm)
Časové okno: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Heart rate (beats per minute) recorded continuously throughout the standardized exercise protocol.
Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Cognitive Heart Rate (bpm)
Časové okno: Measured during cognitive testing immediately before and immediately after the exercise protocol.
Heart rate recorded during standardized cognitive performance tasks.
Measured during cognitive testing immediately before and immediately after the exercise protocol.
Post-Exercise Heart Rate Recovery (bpm)
Časové okno: Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
Heart rate recorded during the post-exercise recovery period.
Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
Cognitive Reaction Time (ms)
Časové okno: Measured immediately before and immediately after the exercise protocol.
Reaction time measured during standardized cognitive tasks (e.g., Psychomotor Vigilance Test, Stroop Test, Flanker Test).
Measured immediately before and immediately after the exercise protocol.
Rating of Perceived Exertion (Borg Scale, points)
Časové okno: Measured immediately after completion of the exercise protocol.
Perceived exertion assessed using the Borg Rating of Perceived Exertion Scale (6-20).
Measured immediately after completion of the exercise protocol.
Biomechanical Kinematic Profile (cm)
Časové okno: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Continuous recording of kinematic parameters derived from wearable sensors, including step length and vertical oscillation.
Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Biomechanical Kinematic Profile (ms)
Časové okno: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Continuous recording of stance time derived from wearable sensor data.
Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Biomechanical Kinematic Profile (steps/min)
Časové okno: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Continuous recording of cadence derived from wearable sensor data.
Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Anthropometric Indices (kg)
Časové okno: Measured at the start of the protocol.
Body mass expressed in kilograms.
Measured at the start of the protocol.
Anthropometric Indices (m)
Časové okno: Measured at the start of the protocol.
Height expressed in metres.
Measured at the start of the protocol.
Body composition (fat-free mass, fat mass) (kg)
Časové okno: Measured at the start of the protocol.
Assessment of body composition (fat-free mass, fat mass) (kg) will be performed at the start of the protocol.
Measured at the start of the protocol.
Body composition (fat-free mass, fat mass) (%)
Časové okno: Measured at the start of the protocol.
Assessment of body composition (fat-free mass, fat mass) (%) will be performed at the start of the protocol.
Measured at the start of the protocol.
Body composition (total body water) (L)
Časové okno: Measured at the start of the protocol.
Assessment of body composition (total body water) (L) will be performed at baseline at the start of the protocol.
Measured at the start of the protocol.
Body composition (total body water) (%)
Časové okno: Measured at the start of the protocol.
Assessment of body composition (total body water) (%) will be performed at baseline at the start of the protocol.
Measured at the start of the protocol.
Exercise Heart Rate Variability (ms)
Časové okno: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Heart rate variability recorded continuously throughout the standardized exercise protocol to assess autonomic regulation.
Continuously monitored during the exercise protocol immediately following administration of the study intervention.
Cognitive Heart Rate Variability (ms)
Časové okno: Measured during cognitive testing immediately before and immediately after the exercise protocol.
Heart rate variability recorded during standardized cognitive performance tasks.
Measured during cognitive testing immediately before and immediately after the exercise protocol.
Post-Exercise Heart Rate Variability Recovery (ms)
Časové okno: Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
Heart rate variability recorded during the post-exercise recovery period.
Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
Cognitive Accuracy (%)
Časové okno: Measured immediately before and immediately after the exercise protocol.
Accuracy measured during standardized cognitive tasks (e.g., Psychomotor Vigilance Test, Stroop Test, Flanker Test).
Measured immediately before and immediately after the exercise protocol.
Performance Expectancy (points)
Časové okno: Measured immediately after completion of the exercise protocol.
Measured immediately before the exercise protocol following administration of the study intervention.
Measured immediately after completion of the exercise protocol.

Spolupracovníci a vyšetřovatelé

Zde najdete lidi a organizace zapojené do této studie.

Sponzor

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. září 2026

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)

3. srpna 2026

Aktualizace studijních záznamů

Poslední zveřejněná aktualizace (Aktuální)

3. srpna 2026

Odeslaná poslední aktualizace, která splnila kritéria kontroly kvality

31. července 2026

Naposledy ověřeno

1. července 2026

Více informací

Termíny související s touto studií

Další identifikační čísla studie

  • 152-1-26
  • 2025/57/N/NZ4/04470 (Jiné číslo grantu/financování: National Science Centre)

Plán pro data jednotlivých účastníků (IPD)

Plánujete sdílet data jednotlivých účastníků (IPD)?

NEROZHODNÝ

Popis plánu IPD

The decision regarding the sharing of individual participant data has not yet been finalized. We are currently evaluating the feasibility, ethical considerations, and data privacy requirements for potential data sharing. A formal plan will be developed and implemented in accordance with institutional policies and regulatory standards upon the completion of the study.

Informace o lécích a zařízeních, studijní dokumenty

Studuje lékový produkt regulovaný americkým FDA

Ne

Studuje produkt zařízení regulovaný americkým úřadem FDA

Ne

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