Clinical Research Directory

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.