Participants use a low-frequency kinetic wellness mat at home 3-4 days/week for 3 weeks. Each day includes a 15-minute supine session on the active mat while recording heart rate variability (HRV), plus 15-minute HRV recordings before bedtime and after waking on those same days. After each session and the next morning, participants complete brief affect check-ins (Self-Assessment Manikin: valence, arousal) and log caffeine/alcohol, exercise, and medications. All participants attend pre- and post-intervention lab visits for questionnaires, resting HRV/EEG, and a brief cognitive test (Trail Making Test). Open-label; schedule matched to control.

Participants complete quiet supine rest at home 3-4 days/week for 3 weeks. Each day includes a 15-minute rest period without vibration while recording HRV, plus 15-minute HRV recordings before bedtime and after waking on those same days. After each session and the next morning, participants complete brief affect check-ins (Self-Assessment Manikin: valence, arousal) and log caffeine/alcohol, exercise, and medications. All participants attend pre- and post-intervention lab visits for questionnaires, resting HRV/EEG, and a brief cognitive test (Trail Making Test). Open-label; schedule matched to the experimental arm.

A noninvasive, horizontal mat that delivers low-frequency mechanical vibration (≈5-16 Hz; peak-to-peak amplitude ≤0.5 mm) while participants lie supine. The active arm uses the mat at home 15 min per session, 3-4 days/week for 3 weeks, preferably in the evening (2-3 h before bedtime). On intervention days, participants record HRV during the 15-min session and complete two additional 15-min HRV recordings (immediately before bedtime and after waking) to index short-term autonomic recovery. Brief affect check-ins (valence, arousal) and logs of caffeine/alcohol, exercise, and medications are completed on those days. Pre- and post-program lab visits include questionnaires plus resting HRV and EEG. The control arm follows the identical schedule without vibration. The device provides no heat or electrical stimulation.

Eyes-closed 15-minute, supine resting EEG using a 24-channel Smarting Mobi system. Preprocessing: 0.5-30 Hz band-pass, ocular SSP, ±100 µV artifact rejection, common-average reference; clean data segmented into 10-s epochs. Outcome is band power in Theta (4-8 Hz), Alpha (8-13 Hz), Beta (13-30 Hz), averaged across all electrodes and epochs (units: power; may be log-transformed for analysis). Higher values indicate stronger oscillatory activity in each band. Primary analysis compares Post-Baseline change between groups.

From the same 15-minute, eyes-closed, supine EEG. Frequency-domain Granger causality computed per 10-s epoch; spectra averaged within Theta (4-8 Hz), Alpha (8-13 Hz), Beta (13-30 Hz). Connectivity summarized across all electrodes via: (a) Global directed strength (mean of all non-diagonal influences; unitless; higher = stronger overall directed connectivity); (b) Nodal inflow and outflow (sum of incoming vs. outgoing influences for each electrode; unitless; higher = stronger received/sent influence); and (c) Pairwise directed influence (value for each electrode pair; unitless). Primary analysis compares Post-Baseline change between groups, with band-specific follow-ups.

Heart rate variability measured during a 15-minute, eyes-closed, supine rest in the lab. Inter-beat intervals captured with Optimal HRV; processed in Kubios (artifact correction; 4 Hz resampling; files with >5% corrected beats excluded; spectral estimates with 300-s windows, 50% overlap). Outcomes reported as:

• RMSSD (ms): Root mean square of successive differences. Higher = greater parasympathetic (vagal) activity.
• HF power (0.15-0.40 Hz, ms²): High-frequency power. Higher = greater parasympathetic activity.

Primary analysis compares change (Post - Baseline) between groups for each metric; an exploratory composite (mean of RMSSD and HF z-scores) may be reported to summarize parasympathetic tone.

Pittsburgh Sleep Quality Index (0-21). Higher scores = worse sleep quality. Outcome is change in global score; report also % with PSQI >5 (poor sleep), if applicable.

Valence and arousal rated 1-9 (single-item pictorial scales). Higher valence = more pleasant; higher arousal = more activated. Outcomes: pre-session levels and pre-session to morning change.