Placebo Effect in Field-Based Physical Performance

NCT07742150 | Not Yet Recruiting

• 2 other identifiers: 152-1-262025/57/N/NZ4/04470
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Physical Performance; Placebo Effect; Cognitive Performance

Keywords

Caffeine; Expectancy; Psychophysiology; Exercise Physiology; Postural Control; Human Performance

Outcome Measures

Primary Outcomes (3)

• Physical Performance Capacity (total distance in running, metres)

  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)

  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)

  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.

Secondary Outcomes (19)

• Exercise Heart Rate (bpm)

  Continuously monitored during the exercise protocol immediately following administration of the study intervention.

• Cognitive Heart Rate (bpm)

  Measured during cognitive testing immediately before and immediately after the exercise protocol.

• Post-Exercise Heart Rate Recovery (bpm)

  Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.

• Cognitive Reaction Time (ms)

  Measured immediately before and immediately after the exercise protocol.

• Rating of Perceived Exertion (Borg Scale, points)

  Measured immediately after completion of the exercise protocol.

Study Arms (3)

Caffeine Group

EXPERIMENTAL

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).

Drug: Caffeine (6mg/kg)

Placebo Group

ACTIVE COMPARATOR

Participants ingest a single dose of placebo (corn starch) in an identical capsule prior to a field-based exercise protocol.

Other: Placebo (Starch capsule)

Control Group

SHAM COMPARATOR

Participants perform the same field-based exercise protocol without ingesting any capsule or active substance.

Other: Sham (No Treatment)

Interventions

Caffeine (6mg/kg) DRUG

Anhydrous caffeine administered in an encapsulated form at a dosage of 6mg per kilogram of body mass, 30-60 minutes before the exercise protocol.

Caffeine Group

Placebo (Starch capsule) OTHER

Corn starch administered in an identical encapsulated form as the active caffeine, 30-60 minutes before the exercise protocol.

Placebo Group

Sham (No Treatment) OTHER

Participants perform the same exercise protocols without any capsule or substance administration.

Control Group

Eligibility Criteria

• Age: 20 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age between 20 and 35 years,
• Healthy adults,
• Regular physical activity,
• Normal or corrected-to-normal vision,
• Habitual caffeine consumption.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Poznan University of Physical Education: lead

Study Sites (1)

Poznan University of Physical Education

Poznan, Greater Poland Voivodeship, Poland

Location

MeSH Terms

Interventions

Caffeine; Starch; salicylhydroxamic acid

Intervention Hierarchy (Ancestors)

Xanthines; Alkaloids; Heterocyclic Compounds; Purinones; Purines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Glucans; Biopolymers; Polymers; Macromolecular Substances; Dietary Carbohydrates; Carbohydrates; Polysaccharides

Study Officials

• Jakub Malik, PhD

  Poznan University of Physical Education, Department of Sports Psychology

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Jakub Malik, PhD

CONTACT

+48739975701; malik@awf.poznan.pl

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants are randomly assigned to one of three parallel groups: Caffeine, Placebo, or Control, with a single testing visit per participant.

Study Record Dates

• First Submitted: July 21, 2026
• First Posted: August 3, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): March 31, 2028
• Study Completion (Estimated): March 31, 2029
• Last Updated: August 3, 2026

Record last verified: 2026-07

Locations

PL (1)