The Effectiveness of the Wim Hof Method on Cardiac Autonomic Function, Blood Pressure, Arterial Compliance, and Different Psychological Parameters

The Wim Hof Method (WHM) is a multi-disciplinary approach to physical and mental well-being combining cold exposure, breathing exercises, and meditation. This study evaluated the effects of a 15-day WHM intervention on cardiovascular parameters at rest and during a cold pressor test (CPT), as well as on various psychological parameters. 42 participants were randomized into an intervention (IG) and a control (CG) group. Throughout the 15-day intervention, the IG performed the WHM daily. The intervention followed the guidelines provided by Wim Hof. The intervention comprised three components: cold water exposure, breathing exercise, and meditation. The participants were instructed to perform the WHM daily over the course of 15 days. The participants could choose when to do so throughout the day, however, the components were to be performed in a strict, sequential order: breathing exercises, followed by meditation, and then cold exposure. Participants were asked to complete a daily log in which they documented whether they performed the procedure and for how long. Altogether, the procedure lasted about 15 minutes. The CG did not receive an intervention throughout the intervention period. Before and after the intervention, systolic (SBP) and diastolic blood pressure (DBP), pulse wave velocity (PWV), heart rate (HR), root mean sum of squared distance (RMSSD), and standard deviation of intervals between successive heartbeats (SDNN) were assessed at rest and during a CPT. Furthermore, perceived stress (PSS), positive affect (PANAS+), negative affect (PANAS-), and subjective vitality (trait (SVSt) and state (SVSs)) was determined.