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Placebo Effect in Field-Based Physical Performance

31 juli 2026 bijgewerkt door: 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.

Studie Overzicht

Toestand

Nog niet aan het werven

Conditie

Interventie / Behandeling

Gedetailleerde beschrijving

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.

Studietype

Ingrijpend

Inschrijving (Geschat)

120

Fase

  • Niet toepasbaar

Contacten en locaties

In dit gedeelte vindt u de contactgegevens van degenen die het onderzoek uitvoeren en informatie over waar dit onderzoek wordt uitgevoerd.

Studiecontact

Studie Locaties

  • Polen
    • Greater Poland Voivodeship
      • Poznan, Greater Poland Voivodeship, Polen
        • Poznań University of Physical Education
        • Contact:

Deelname Criteria

Onderzoekers zoeken naar mensen die aan een bepaalde beschrijving voldoen, de zogenaamde geschiktheidscriteria. Enkele voorbeelden van deze criteria zijn iemands algemene gezondheidstoestand of eerdere behandelingen.

Geschiktheidscriteria

Leeftijden die in aanmerking komen voor studie

  • Volwassen

Accepteert gezonde vrijwilligers

Ja

Beschrijving

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.

Studie plan

Dit gedeelte bevat details van het studieplan, inclusief hoe de studie is opgezet en wat de studie meet.

Hoe is de studie opgezet?

Ontwerpdetails

  • Primair doel: Fundamentele wetenschap
  • Toewijzing: Gerandomiseerd
  • Interventioneel model: Parallelle opdracht
  • Masker: Verviervoudigen

Wapens en interventies

Deelnemersgroep / Arm
Interventie / Behandeling
Experimenteel: 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).
Geneesmiddel: Caffeine (6mg/kg)
Anhydrous caffeine administered in an encapsulated form at a dosage of 6mg per kilogram of body mass, 30-60 minutes before the exercise protocol.
Actieve vergelijker: Placebo Group
Participants ingest a single dose of placebo (corn starch) in an identical capsule prior to a field-based exercise protocol.
Ander: Placebo (Starch capsule)
Corn starch administered in an identical encapsulated form as the active caffeine, 30-60 minutes before the exercise protocol.
Sham-vergelijker: Control Group
Participants perform the same field-based exercise protocol without ingesting any capsule or active substance.
Ander: Sham (No Treatment)
Participants perform the same exercise protocols without any capsule or substance administration.

Wat meet het onderzoek?

Primaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Physical Performance Capacity (total distance in running, metres)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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.

Secundaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Exercise Heart Rate (bpm)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: Measured at the start of the protocol.
Body mass expressed in kilograms.
Measured at the start of the protocol.
Anthropometric Indices (m)
Tijdsspanne: 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)
Tijdsspanne: 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) (%)
Tijdsspanne: 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)
Tijdsspanne: 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) (%)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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)
Tijdsspanne: 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 (%)
Tijdsspanne: 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)
Tijdsspanne: 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.

Medewerkers en onderzoekers

Hier vindt u mensen en organisaties die betrokken zijn bij dit onderzoek.

Sponsor

Poznan University of Physical Education

Onderzoekers

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

Studie record data

Deze datums volgen de voortgang van het onderzoeksdossier en de samenvatting van de ingediende resultaten bij ClinicalTrials.gov. Studieverslagen en gerapporteerde resultaten worden beoordeeld door de National Library of Medicine (NLM) om er zeker van te zijn dat ze voldoen aan specifieke kwaliteitscontrolenormen voordat ze op de openbare website worden geplaatst.

Bestudeer belangrijke data

Studie start (Geschat)

1 september 2026

Primaire voltooiing (Geschat)

31 maart 2028

Studie voltooiing (Geschat)

31 maart 2029

Studieregistratiedata

Eerst ingediend

21 juli 2026

Eerst ingediend dat voldeed aan de QC-criteria

31 juli 2026

Eerst geplaatst (Werkelijk)

3 augustus 2026

Updates van studierecords

Laatste update geplaatst (Werkelijk)

3 augustus 2026

Laatste update ingediend die voldeed aan QC-criteria

31 juli 2026

Laatst geverifieerd

1 juli 2026

Meer informatie

Termen gerelateerd aan deze studie

Trefwoorden

Aanvullende relevante MeSH-voorwaarden

Andere studie-ID-nummers

  • 152-1-26
  • 2025/57/N/NZ4/04470 (Ander subsidie-/financieringsnummer: National Science Centre)

Plan Individuele Deelnemersgegevens (IPD)

Bent u van plan om gegevens van individuele deelnemers (IPD) te delen?

ONBESLIST

Beschrijving IPD-plan

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.

Informatie over medicijnen en apparaten, studiedocumenten

Bestudeert een door de Amerikaanse FDA gereguleerd geneesmiddel

Nee

Bestudeert een door de Amerikaanse FDA gereguleerd apparaatproduct

Nee

Deze informatie is zonder wijzigingen rechtstreeks van de website clinicaltrials.gov gehaald. Als u verzoeken heeft om uw onderzoeksgegevens te wijzigen, te verwijderen of bij te werken, neem dan contact op met register@clinicaltrials.gov. Zodra er een wijziging wordt doorgevoerd op clinicaltrials.gov, wordt deze ook automatisch bijgewerkt op onze website .

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