Pain Perception and Exercise-Induced Hypoalgesia Across Circadian Rhythms

NCT07290465 | Not Yet Recruiting

• 1 other identifier: E-10840098-202.3.02-1597
• Study Type: interventional
• Target: 56
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this randomized crossover clinical trial is to investigate whether exercise-induced hypoalgesia (EIH) is influenced by circadian rhythm in healthy adults aged 18-40 years. The main questions it aims to answer are:

• Does the time of day (morning vs. evening) influence changes in pain perception following exercise?
• Do chronotype, sex, or stimulation site (bony vs. muscular) alter the magnitude of this effect? Participants will:
• Complete questionnaires
• Undergo quantitative sensory testing
• Attend both morning and evening sessions in randomized crossover order

Conditions

Circadian Rhythm; Pain Perception; Healthy Participants; Chronotype; Physical Therapy; Exercise Induced Hypoalgesia

Keywords

Exercise-Induced Hypoalgesia; Pain Perception; Circadian Rhythm; Chronotype; Healthy Participants; High-Intensity Functional Training; Supervised Deep Breathing; Pressure Pain Threshold (PPT); Pain pressure tolerance threshold (PPTol); Quantative Sensory Testing; Bony Landmarks; Muscular Landmarks; Physical Therapy; Randomized Control Trial; Crossover; Pain Management

Outcome Measures

Primary Outcomes (2)

• Pressure Pain Threshold (PPT)

  Pressure Pain Threshold (PPT) will be measured using an algometer at standardized bony and muscular landmarks. Pressure Pain Threshold (PPT) is defined as the minimal pressure at which a participant first perceives pain. Changes in Pressure Pain Threshold (PPT) will be used to assess the magnitude of exercise-induced hypoalgesia (EIH). Unit: kg/cm²

  Baseline (0 minute before intervention) and immediately post-intervention (within 2 minutes) Measured in both high intensity functional training (HIFT) and supervised deep-breathing conditions during each morning and evening session

• Pressure Pain Tolerance (PPTol)

  Pressure Pain Tolerance (PPTol) will be measured using an algometer at standardized bony and muscular landmarks. Pressure Pain Tolerance (PPTol) is defined as the maximal pressure the participant is willing to tolerate. Changes in Pressure Pain Tolerance (PPTol) will be used to assess pain modulation in response to exercise across circadian phases. Unit: kg/cm²

  Baseline (0 minute before intervention) and immediately post-intervention (within 2 minutes) Measured in both high intensity functional training (HIFT) and supervised deep-breathing conditions during each morning and evening session

Secondary Outcomes (7)

• Munich Chronotype Questionnaire (MCTQ)

  Baseline (before any intervention session)

• Pain Catastrophizing (PCS)

  Baseline (before any intervention session)

• Fear of Pain (FPQ-9)

  Baseline (before any intervention session)

• Brief Version of the Pittsburgh Sleep Quality Index (B-PSQI)

  Baseline (before any intervention session)

• Depression Anxiety Stress Scales (DASS-21)

  Baseline (before any intervention session)

Study Arms (2)

Morning Chronotype

EXPERIMENTAL

Participants classified as morning chronotype using the Munich Chronotype Questionnaire (MCTQ) will attend both a morning session and an evening session in randomized order with at least 72 hours between visits. Within each session the participant completes both a 12-minute supervised deep-breathing control condition and a 12-minute High-Intensity Functional Training (HIFT) intervention, separated by a 30-minute break to minimize carryover effects. Pain perception is assessed before and after each condition.

Behavioral: High-Intensity Functional Training (HIFT); Behavioral: Supervised Deep Breathing

Evening Chronotype

EXPERIMENTAL

Participants classified as evening chronotype using the Munich Chronotype Questionnaire (MCTQ) will attend both a morning session and an evening session in randomized order with at least 72 hours between visits. Within each session the participant completes both a 12-minute supervised deep-breathing control condition and a 12-minute High-Intensity Functional Training (HIFT) intervention, separated by a 30-minute break to minimize carryover effects. Pain perception is assessed before and after each condition.

Behavioral: High-Intensity Functional Training (HIFT); Behavioral: Supervised Deep Breathing

Interventions

High-Intensity Functional Training (HIFT) BEHAVIORAL

A 12-minute, instructor-led HIFT protocol delivered via the same video to all participants. After a 5-minute warm-up, participants perform six exercises targeting major muscle groups. The exercises are 4 lunges followed by one push-up, 10 high knees followed by 10 shuffles, burpees, squat jumps, skaters, and plank up-downs. Each exercise is done for 40 seconds then 20 seconds rest. The cycle repeats twice for a total of 12 minutes. Rate of Perceived Exertion (Borg scale) is recorded at baseline, post-warmup, during each rest interval, and immediately post-exercise. A physiotherapist supervises performance, ensures correct technique, and enforces safety and target intensity while motivating and encouraging the participant.

Evening Chronotype; Morning Chronotype

Supervised Deep Breathing BEHAVIORAL

A 12-minute deep breathing session delivered via a prerecorded audio and supervised by a physiotherapist. The breathing rhythm includes inhaling for 4 seconds and exhaling for 6 seconds for a total 1 minute, followed by 1 minute of normal breathing. This cycle is repeated six times for a total duration of 12 minutes. Participants lie supine in a comfortable position and wear headphones. A self-reported Rate of Perceived Relaxation (RPR, 0-10) is recorded before and after. This serves as a non-exercise control to account for relaxation and attention effects.

Evening Chronotype; Morning Chronotype

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy participants
• age 18 to 40 years
• good level of English that allow the enrolled participant to provide informed consent and complete the questionnaires provided
• being categorized as "moderate" in the International Physical Activity Questionnaire (IPAQ)

You may not qualify if:

• inability to report pain intensity reliably
• consumption of narcotics or tobacco products
• regularly taking pain medications and analgesics
• pregnant or planning to get pregnant
• surgery within the last 12 months
• acute or chronic pain conditions
• uncontrolled hypertension
• cardiovascular diseases, pulmonary diseases, neurological diseases with significant changes in somatosensory and pain perception, metabolic diseases, serious systemic diseases or conditions that restrict normal daily activities, inflammatory conditions (e.g. rheumatoid arthritis), or orthopedic injuries
• intolerable pain during the pain perception test
• serious psychiatric conditions (e.g., schizophrenia and bipolar disorder) or psychological disorders (e.g., depression) that may affect pain thresholds (16).
• Severe sleep disorders and circadian rhythm disturbances
• BMI \> 30
• serious fatigue or delayed-onset muscle soreness (9) at least 24 h after exercise sessions or a sudden change in activity for more than one week

Sponsors & Collaborators

• Medipol University: lead

Study Sites (1)

Istanbul Medipol University

Istanbul, Beykoz, 34810, Turkey (Türkiye)

Location

Related Links

• The revised International Association for the Study of Pain definition of pain: concepts, challenges, and compromises.
• A meta-analytic review of the hypoalgesic effects of exercise
• Exercise induced hypoalgesia after a high intensity functional training: a randomized controlled crossover study
• Quantitative sensory testing: a practical guide and clinical applications
• Day-to-day reliability of pressure pain threshold and pain ratings in college-aged men. International journal of rehabilitation research.
• New Insights Into the Circadian Rhythm and Its Related Diseases.

MeSH Terms

Conditions

Agnosia

Condition Hierarchy (Ancestors)

Perceptual Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Gizem Ergezen Şahin, Dr. Assistant Professor

  Department of Physiotherapy and Rehabilitation/Istanbul Medipol University

  STUDY DIRECTOR

Central Study Contacts

Fatema Mohamed Soliman, PT, MSc (Cand.)

CONTACT

+90 537 736 20 79; pt.fatemasoliman@gmail.com

Aliaa Salem Menshawi, PT, MSc (Cand.)

CONTACT

+905527304660; aliaamenshawi@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: Both the participant and assessor will be masked to the individual's chronotype
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Participants who completed the morning sessions will cross over to the evening sessions and vice versa in a randomized order with a washout period.

Study Record Dates

• First Submitted: November 14, 2025
• First Posted: December 18, 2025
• Study Start: January 1, 2026
• Primary Completion: March 1, 2026
• Study Completion: April 1, 2026
• Last Updated: December 18, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)