Eyes-Closed Interoceptive Aerobic Exercise Compared With Matched Eyes-Open Treadmill Exercise in Healthy Adults (ECI-AE Pilot)

Feasibility, Acceptability, Psychophysiological Responses, and Cognitive Effects of Prototype Eyes-Closed Interoceptive Aerobic Exercise Versus Matched Eyes-Open Treadmill Exercise: A Randomized Repeated-Exposure Crossover Pilot Trial

This completed single-site pilot trial evaluated a prototype eyes-closed interoceptive aerobic exercise condition compared with a matched eyes-open treadmill control condition in healthy adults. Participants attended one baseline/familiarization visit followed by four randomized experimental treadmill visits. Each participant completed the eyes-closed interoceptive aerobic exercise condition twice and the matched eyes-open control condition twice in one of two randomized sequences. Both conditions used the same individualized 25-minute treadmill protocol, 0% incline, safety harness, front-handle contact requirement, laboratory supervision, and staff-controlled speed transitions. The conditions differed in eye status, attentional instructions, and audio environment. The broader pilot project collected feasibility, safety, fidelity, acceptability, adaptation, affective-experience, cardiovascular/autonomic, blood-pressure, and cognitive-performance outcomes.

Study Overview

• Status: Completed
• Conditions: Physical Activity; Exercise; Healthy Adult; Interoception; Affect and Exertion During and Post-exercise
• Intervention / Treatment: Behavioral: Eyes-Closed Interoceptive Aerobic Exercise; Behavioral: Matched Eyes-Open Treadmill Exercise

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Virginia
    • Norfolk, Virginia, United States, 23529-5000
      • Old Dominion University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 18 to 45 years
• Prior experience exercising on a treadmill
• Able and willing to attend one baseline/familiarization visit and four experimental laboratory visits
• Able to complete supervised treadmill walking and jogging exercise under laboratory safety procedures
• Able to provide informed consent

Exclusion Criteria:

• Physical health condition that would preclude safe participation in treadmill exercise
• Pregnancy
• Hypertension
• Cardiac disorder
• Arteriovenous shunt
• Intravascular therapy
• Blood-flow problems
• Mastectomy
• Mental health condition that would preclude safe participation in treadmill exercise
• Diagnosed depression
• Diagnosed anxiety
• Any other condition or safety concern identified by study staff that would make participation unsafe or inappropriate

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sequence 1: Control, ECI-AE, Control, ECI-AE; Participants randomized to Sequence 1 completed the matched eyes-open treadmill control condition at experimental visits 1 and 3 and the eyes-closed interoceptive aerobic exercise condition at experimental visits 2 and 4. The same individualized 25-minute treadmill protocol, determined during the baseline/familiarization visit, was used across all four experimental visits.	Behavioral: Eyes-Closed Interoceptive Aerobic Exercise; Eyes-closed interoceptive aerobic exercise was a prototype multicomponent treadmill exercise condition. Participants completed the individualized 25-minute treadmill protocol at 0% incline using five consecutive 5-minute phases: walking, brisk walking, jogging or faster walking, faster jogging or fastest walking, and walking recovery. Participants kept their eyes closed, wore a safety harness, and maintained light contact with the front treadmill handle for positional reference. Before the bout, participants were instructed to close their eyes, clear their mind, and focus on breathing. During exercise, soft meditative background music was played continuously, and brief prerecorded reminders were delivered every 2.5 minutes: "clear the mind," "focus on breathing," and "close your eyes." Before each experimental treadmill session in both conditions, participants were told they could breathe through the nose when possible.; Other Names: ECI-AE; Eyes-closed interoceptive treadmill exercise; Prototype eyes-closed interoceptive aerobic exercise; Behavioral: Matched Eyes-Open Treadmill Exercise; The matched eyes-open treadmill exercise condition used the same individualized 25-minute treadmill protocol, 0% incline, five-phase structure, safety harness, front-handle contact requirement, laboratory supervision, and staff-controlled speed transitions as ECI-AE. Participants kept their eyes open. Before the bout, participants were told that a science audiobook would be played and that they could attend to or ignore it. No ECI-AE verbal reminders or meditative background music were delivered. The audiobook provided a standardized externally oriented audio context and avoided exercise-, emotion-, or meditation-related content. Before each experimental treadmill session in both conditions, participants were told they could breathe through the nose when possible.; Other Names: Eyes-open treadmill control; Conventional eyes-open treadmill exercise
Experimental: Sequence 2: ECI-AE, Control, ECI-AE, Control; Participants randomized to Sequence 2 completed the eyes-closed interoceptive aerobic exercise condition at experimental visits 1 and 3 and the matched eyes-open treadmill control condition at experimental visits 2 and 4. The same individualized 25-minute treadmill protocol, determined during the baseline/familiarization visit, was used across all four experimental visits.	Behavioral: Eyes-Closed Interoceptive Aerobic Exercise; Eyes-closed interoceptive aerobic exercise was a prototype multicomponent treadmill exercise condition. Participants completed the individualized 25-minute treadmill protocol at 0% incline using five consecutive 5-minute phases: walking, brisk walking, jogging or faster walking, faster jogging or fastest walking, and walking recovery. Participants kept their eyes closed, wore a safety harness, and maintained light contact with the front treadmill handle for positional reference. Before the bout, participants were instructed to close their eyes, clear their mind, and focus on breathing. During exercise, soft meditative background music was played continuously, and brief prerecorded reminders were delivered every 2.5 minutes: "clear the mind," "focus on breathing," and "close your eyes." Before each experimental treadmill session in both conditions, participants were told they could breathe through the nose when possible.; Other Names: ECI-AE; Eyes-closed interoceptive treadmill exercise; Prototype eyes-closed interoceptive aerobic exercise; Behavioral: Matched Eyes-Open Treadmill Exercise; The matched eyes-open treadmill exercise condition used the same individualized 25-minute treadmill protocol, 0% incline, five-phase structure, safety harness, front-handle contact requirement, laboratory supervision, and staff-controlled speed transitions as ECI-AE. Participants kept their eyes open. Before the bout, participants were told that a science audiobook would be played and that they could attend to or ignore it. No ECI-AE verbal reminders or meditative background music were delivered. The audiobook provided a standardized externally oriented audio context and avoided exercise-, emotion-, or meditation-related content. Before each experimental treadmill session in both conditions, participants were told they could breathe through the nose when possible.; Other Names: Eyes-open treadmill control; Conventional eyes-open treadmill exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number and Percentage of Participants Reaching Each Recruitment and Participation Milestone	Recruitment and participant flow were summarized as the number and percentage of individuals who were screened, preliminarily eligible, ineligible, individually contacted or offered participation, not contacted because recruitment ended, nonresponsive, declined, consented and completed the baseline/familiarization visit, withdrew before randomization, randomized, and completed all experimental visits.	From screening through the fifth laboratory visit, up to 6 weeks per participant
Number and Percentage of Randomized Participants Who Completed All Experimental Visits	Post-randomization retention was summarized as the number and percentage of randomized participants who completed all four experimental visits. Reasons for post-randomization withdrawal or noncompletion were documented when available.	From randomization after the baseline/familiarization visit through the fifth laboratory visit, an average of 32 days
Number and Percentage of Planned Experimental Sessions Completed	Experimental session completion was summarized as the number and percentage of planned experimental sessions that were started and the number and percentage of started sessions in which participants completed the full 25-minute treadmill bout. Session completion was summarized overall and by condition.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Number of Participants With Safety Events During Experimental Treadmill Sessions	Safety was summarized as the number of participants with documented adverse events, near-falls, safety-harness events, participant requests to stop, early stops due to dizziness, pain, unusual shortness of breath, discomfort, loss of balance, unsafe positioning, equipment malfunction, or staff judgment that continuing would be unsafe.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Mean Feeling Scale Score During Each Treadmill Exercise Phase	Emotional feeling was measured using the Feeling Scale, an 11-point single-item measure ranging from -5 to +5, with higher scores indicating more positive affective valence. Mean or model-estimated mean scores were summarized by condition and treadmill phase.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Mean Physical Comfort/Tiredness Rating During Each Treadmill Exercise Phase	Physical comfort/tiredness was measured using an 11-point single-item rating ranging from -5 to +5, with higher scores indicating greater physical comfort or lower tiredness. Mean or model-estimated mean scores were summarized by condition and treadmill phase.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number and Percentage of Experimental Sessions Delivered as Planned	Protocol fidelity was summarized as the number and percentage of started experimental sessions delivered using the participant-specific treadmill speed protocol, assigned audio condition, safety harness, front-handle contact procedure, and planned 25-minute treadmill duration, without documented protocol deviations.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Percentage of Expected Affective-Experience and Acceptability Data Obtained	Data completeness was summarized as the percentage of expected observations obtained for emotional feeling, physical comfort/tiredness, perceived attentional/interoceptive cue-following, and final comparative interview responses.	From the second laboratory visit through the final comparative interview at the fifth laboratory visit, an average of 24 days
Mean Custom Perceived Attentional and Interoceptive Cue-Following Rating Score	Perceived attentional and interoceptive cue-following was measured after each experimental treadmill session using a custom single-item scale titled the Perceived Attentional and Interoceptive Cue-Following Rating. Possible scores ranged from 1 to 10. Higher scores indicate greater perceived success clearing the mind and focusing on breathing during exercise, representing stronger engagement with the intended attentional and interoceptive exercise instructions. Mean scores were summarized by condition and exposure.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Number and Percentage of Participants Reporting Condition Preference	Condition preference was summarized as the number and percentage of participants who preferred ECI-AE, preferred the matched eyes-open control condition, or reported no preference during the final comparative interview.	From the baseline/familiarization visit through the final comparative interview at the fifth laboratory visit, an average of 32 days
Number and Percentage of Participants Reporting Better, Worse, or Same Second ECI-AE Exposure	Adaptation to ECI-AE was summarized as the number and percentage of participants who described the second ECI-AE exposure as better, worse, or the same compared with the first ECI-AE exposure. Open-ended explanations were used to characterize perceived familiarity, comfort, confidence, or remaining concerns.	From the baseline/familiarization visit through the final comparative interview at the fifth laboratory visit, an average of 32 days
Mean Postexercise Seated-Recovery Feeling Scale Score	Postexercise seated-recovery emotional feeling was measured using the Feeling Scale, an 11-point single-item measure ranging from -5 to +5, with higher scores indicating more positive affective valence. Mean scores were summarized by condition and exposure.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Mean Postexercise Seated-Recovery Physical Comfort/Tiredness Rating	Postexercise seated-recovery physical comfort/tiredness was measured using an 11-point single-item rating ranging from -5 to +5, with higher scores indicating greater physical comfort or lower tiredness. Mean scores were summarized by condition and exposure.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Change From Pre-Session to Post-Session State Anxiety Score	State anxiety was measured before and after each experimental session using the State-Trait Anxiety Inventory-State Form. The scale includes 20 items rated from 1 to 4, producing a total score ranging from 20 to 80 after appropriate reverse scoring. Higher scores indicate greater state anxiety. Change scores were calculated as post-session score minus pre-session score and summarized by condition.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Change From Pre-Session to Post-Session Affective State Score	Exercise-induced affective state was measured before and after each experimental session using the Exercise-Induced Affect Scale questionnaire. Mean item scores ranged from 1 to 5, with higher scores indicating greater intensity of the specific affective state being rated. Change scores were calculated as post-session score minus pre-session score and summarized by condition.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Mean Post-Session Condition-Specific Exercise Attitude Score	Exercise attitude was measured after each experimental session using custom bipolar adjective ratings of the completed exercise condition. Items were rated from 1 to 9. Higher scores indicate a more favorable attitude toward the completed exercise condition. Mean scores were summarized by condition.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Mean Post-Session Condition-Specific Exercise Intention Score	Exercise intention was measured after each experimental session using custom condition-specific items rated from 1 to 5. Higher scores indicate stronger intention to perform the relevant exercise type in the future. After matched eyes-open control sessions, items assessed intention and motivation for treadmill exercise. After ECI-AE sessions, items assessed intention and motivation for meditation-infused or eyes-closed interoceptive aerobic exercise. Mean scores were summarized by condition.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Heart Rate During Treadmill Exercise and Recovery	Heart rate was recorded in beats per minute using a heart-rate strap during experimental visits. Mean heart rate values were summarized during the 25-minute treadmill exercise bout and postexercise seated recovery period by condition, session, treadmill phase, or recovery period. Higher values indicate higher heart rate in beats per minute.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Mean Heart-Rate Variability During Seated Rest and Recovery	Heart-rate variability was derived from heart-rate recordings collected during seated rest and postexercise seated recovery periods. HRV indices, such as root mean square of successive differences or other protocol-specified HRV metrics, were summarized by condition and time period. Higher scores indicate greater heart-rate variability for the specific HRV metric reported.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Change From Pre-Exercise to Postexercise Systolic and Diastolic Blood Pressure	Systolic and diastolic blood pressure were measured in millimeters of mercury before treadmill exercise, immediately after treadmill exercise, and after postexercise seated recovery at each experimental visit. Change scores were summarized by condition. Higher values indicate higher blood pressure.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Change From Pre-Exercise to Postexercise Stroop Task Performance	Cognitive performance was measured using a Stroop task before and after the treadmill exercise and recovery procedures at each experimental visit. Outcomes included reaction time, accuracy, and/or Stroop interference indicators. For reaction time and interference scores, higher values generally indicate slower or greater interference. For accuracy, higher values indicate better performance.	From the second laboratory visit through the fifth laboratory visit, an average of 24 days
Number of Participants Reporting Open-Ended Acceptability and Experience Themes	Open-ended responses from the final comparative interview were coded to summarize participant-reported reasons for better, worse, or similar experiences between ECI-AE and the matched control condition. Themes included perceived benefits, burdens, safety concerns, adaptation, breathing focus, mental quiet, physical tiredness, music or audio experience, and condition preference. The number of participants endorsing each theme was summarized.	From the baseline/familiarization visit through the final comparative interview at the fifth laboratory visit, an average of 32 days

Collaborators and Investigators

• Sponsor: Old Dominion University

Study record dates

Study Major Dates

• Study Start (Actual): October 20, 2024
• Primary Completion (Actual): December 22, 2025
• Study Completion (Actual): December 22, 2025

Study Registration Dates

• First Submitted: May 13, 2026
• First Submitted That Met QC Criteria: May 28, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Behavior; Motor Activity
• Other Study ID Numbers: ODU-ECIAE-PILOT-001; 2169561-6 (Other Identifier: Old Dominion University)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The study team is evaluating whether de-identified individual participant quantitative data can be shared in accordance with institutional review board requirements, participant consent, and institutional data-use policies. Qualitative interview or open-ended response data may be restricted because of participant confidentiality and potential re-identification risk in a small single-site pilot sample.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No