Marcy and Jack dig into a nineteen ninety-eight study where a month of heart-coherence practice was linked to twenty-three percent lower cortisol and doubled DHEA — with the honest caveats held — plus the two-minute recalibration practice. Read the paper: The Impact of a New Emotional Self-Management Program on Stress, Emotions, Heart Rate Variability, DHEA and Cortisol (Rollin McCraty, Bob Barrios-Choplin, Deborah Rozman, Mike Atkinson, Alan D. Watkins, 1998, Integrative Physiological and Behavioral Science) — https://www.heartmath.org/research/research-library/clinical-health-research/impact-of-emotional-self-management-program-on-stress-emotions-hrv-dhea-cortisol/