Placebo Effect in Field-Based Physical Performance
31 de julho de 2026 atualizado por: 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.
Visão geral do estudo
Status
Ainda não está recrutando
Intervenção / Tratamento
Descrição detalhada
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.
Tipo de estudo
Intervencional
Inscrição (Estimado)
120
Estágio
- Não aplicável
Contactos e Locais
Esta seção fornece os detalhes de contato para aqueles que conduzem o estudo e informações sobre onde este estudo está sendo realizado.
Contato de estudo
- Nome: Jakub Malik, PhD
- Número de telefone: +48739975701
- E-mail: malik@awf.poznan.pl
Locais de estudo
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Greater Poland Voivodeship
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Poznan, Greater Poland Voivodeship, Polônia
- Poznań University of Physical Education
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Contato:
- Jakub Malik, PhD
- Número de telefone: +48739975701
- E-mail: malik@awf.poznan.pl
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Critérios de participação
Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.
Critérios de elegibilidade
Idades elegíveis para estudo
- Adulto
Aceita Voluntários Saudáveis
Sim
Descrição
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.
Plano de estudo
Esta seção fornece detalhes do plano de estudo, incluindo como o estudo é projetado e o que o estudo está medindo.
Como o estudo é projetado?
Detalhes do projeto
- Finalidade Principal: Ciência básica
- Alocação: Randomizado
- Modelo Intervencional: Atribuição Paralela
- Mascaramento: Quadruplicar
Armas e Intervenções
Grupo de Participantes / Braço |
Intervenção / Tratamento |
|---|---|
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Experimental: 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).
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Anhydrous caffeine administered in an encapsulated form at a dosage of 6mg per kilogram of body mass, 30-60 minutes before the exercise protocol.
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Comparador Ativo: Placebo Group
Participants ingest a single dose of placebo (corn starch) in an identical capsule prior to a field-based exercise protocol.
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Corn starch administered in an identical encapsulated form as the active caffeine, 30-60 minutes before the exercise protocol.
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Comparador Falso: Control Group
Participants perform the same field-based exercise protocol without ingesting any capsule or active substance.
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Participants perform the same exercise protocols without any capsule or substance administration.
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O que o estudo está medindo?
Medidas de resultados primários
Medida de resultado |
Descrição da medida |
Prazo |
|---|---|---|
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Physical Performance Capacity (total distance in running, metres)
Prazo: Measured during the exercise protocol immediately following administration of the study intervention.
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Total physical work capacity measured as the total running distance (metres) completed during the standardized exercise protocol.
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Measured during the exercise protocol immediately following administration of the study intervention.
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Physical Performance Capacity (total work in Joules for cycling)
Prazo: Measured during the exercise protocol immediately following administration of the study intervention.
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Total physical work capacity measured as the total mechanical work (Joules) completed during the standardized cycling exercise protocol.
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Measured during the exercise protocol immediately following administration of the study intervention.
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Physical Performance Capacity (exercise duration until exhaustion, minutes)
Prazo: Measured during the exercise protocol immediately following administration of the study intervention.
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Total physical work capacity measured as exercise duration until volitional exhaustion during the standardized exercise protocol.
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Measured during the exercise protocol immediately following administration of the study intervention.
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Medidas de resultados secundários
Medida de resultado |
Descrição da medida |
Prazo |
|---|---|---|
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Exercise Heart Rate (bpm)
Prazo: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Heart rate (beats per minute) recorded continuously throughout the standardized exercise protocol.
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Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Cognitive Heart Rate (bpm)
Prazo: Measured during cognitive testing immediately before and immediately after the exercise protocol.
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Heart rate recorded during standardized cognitive performance tasks.
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Measured during cognitive testing immediately before and immediately after the exercise protocol.
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Post-Exercise Heart Rate Recovery (bpm)
Prazo: Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
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Heart rate recorded during the post-exercise recovery period.
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Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
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Cognitive Reaction Time (ms)
Prazo: Measured immediately before and immediately after the exercise protocol.
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Reaction time measured during standardized cognitive tasks (e.g., Psychomotor Vigilance Test, Stroop Test, Flanker Test).
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Measured immediately before and immediately after the exercise protocol.
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Rating of Perceived Exertion (Borg Scale, points)
Prazo: Measured immediately after completion of the exercise protocol.
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Perceived exertion assessed using the Borg Rating of Perceived Exertion Scale (6-20).
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Measured immediately after completion of the exercise protocol.
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Biomechanical Kinematic Profile (cm)
Prazo: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Continuous recording of kinematic parameters derived from wearable sensors, including step length and vertical oscillation.
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Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Biomechanical Kinematic Profile (ms)
Prazo: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Continuous recording of stance time derived from wearable sensor data.
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Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Biomechanical Kinematic Profile (steps/min)
Prazo: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Continuous recording of cadence derived from wearable sensor data.
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Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Anthropometric Indices (kg)
Prazo: Measured at the start of the protocol.
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Body mass expressed in kilograms.
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Measured at the start of the protocol.
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Anthropometric Indices (m)
Prazo: Measured at the start of the protocol.
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Height expressed in metres.
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Measured at the start of the protocol.
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Body composition (fat-free mass, fat mass) (kg)
Prazo: Measured at the start of the protocol.
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Assessment of body composition (fat-free mass, fat mass) (kg) will be performed at the start of the protocol.
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Measured at the start of the protocol.
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Body composition (fat-free mass, fat mass) (%)
Prazo: Measured at the start of the protocol.
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Assessment of body composition (fat-free mass, fat mass) (%) will be performed at the start of the protocol.
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Measured at the start of the protocol.
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Body composition (total body water) (L)
Prazo: Measured at the start of the protocol.
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Assessment of body composition (total body water) (L) will be performed at baseline at the start of the protocol.
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Measured at the start of the protocol.
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Body composition (total body water) (%)
Prazo: Measured at the start of the protocol.
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Assessment of body composition (total body water) (%) will be performed at baseline at the start of the protocol.
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Measured at the start of the protocol.
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Exercise Heart Rate Variability (ms)
Prazo: Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Heart rate variability recorded continuously throughout the standardized exercise protocol to assess autonomic regulation.
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Continuously monitored during the exercise protocol immediately following administration of the study intervention.
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Cognitive Heart Rate Variability (ms)
Prazo: Measured during cognitive testing immediately before and immediately after the exercise protocol.
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Heart rate variability recorded during standardized cognitive performance tasks.
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Measured during cognitive testing immediately before and immediately after the exercise protocol.
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Post-Exercise Heart Rate Variability Recovery (ms)
Prazo: Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
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Heart rate variability recorded during the post-exercise recovery period.
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Continuously monitored during the first 5 minutes immediately following completion of the exercise protocol.
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Cognitive Accuracy (%)
Prazo: Measured immediately before and immediately after the exercise protocol.
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Accuracy measured during standardized cognitive tasks (e.g., Psychomotor Vigilance Test, Stroop Test, Flanker Test).
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Measured immediately before and immediately after the exercise protocol.
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Performance Expectancy (points)
Prazo: Measured immediately after completion of the exercise protocol.
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Measured immediately before the exercise protocol following administration of the study intervention.
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Measured immediately after completion of the exercise protocol.
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Colaboradores e Investigadores
É aqui que você encontrará pessoas e organizações envolvidas com este estudo.
Patrocinador
Investigadores
- Investigador principal: Jakub Malik, PhD, Poznan University of Physical Education, Department of Sports Psychology
Datas de registro do estudo
Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.
Datas Principais do Estudo
Início do estudo (Estimado)
1 de setembro de 2026
Conclusão Primária (Estimado)
31 de março de 2028
Conclusão do estudo (Estimado)
31 de março de 2029
Datas de inscrição no estudo
Enviado pela primeira vez
21 de julho de 2026
Enviado pela primeira vez que atendeu aos critérios de CQ
31 de julho de 2026
Primeira postagem (Real)
3 de agosto de 2026
Atualizações de registro de estudo
Última Atualização Postada (Real)
3 de agosto de 2026
Última atualização enviada que atendeu aos critérios de controle de qualidade
31 de julho de 2026
Última verificação
1 de julho de 2026
Mais Informações
Termos relacionados a este estudo
Palavras-chave
Termos MeSH relevantes adicionais
Outros números de identificação do estudo
- 152-1-26
- 2025/57/N/NZ4/04470 (Número de outro subsídio/financiamento: National Science Centre)
Plano para dados de participantes individuais (IPD)
Planeja compartilhar dados de participantes individuais (IPD)?
INDECISO
Descrição do plano 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.
Informações sobre medicamentos e dispositivos, documentos de estudo
Estuda um medicamento regulamentado pela FDA dos EUA
Não
Estuda um produto de dispositivo regulamentado pela FDA dos EUA
Não
Essas informações foram obtidas diretamente do site clinicaltrials.gov sem nenhuma alteração. Se você tiver alguma solicitação para alterar, remover ou atualizar os detalhes do seu estudo, entre em contato com register@clinicaltrials.gov. Assim que uma alteração for implementada em clinicaltrials.gov, ela também será atualizada automaticamente em nosso site .