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 Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
40
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.
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.
Old Dominion University
Norfolk, Virginia, United States
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: From the second laboratory visit through the fifth laboratory visit, an average of 24 days
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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
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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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: From the second laboratory visit through the fifth laboratory visit, an average of 24 days