Comparing the Effectiveness of a Mindfulness-Based Intervention and Progressive Muscle Relaxation in a Military Context

Abstract

Objectives: While stressors of military deployment are known to have profound effects on health, less is known about effective methods for promoting health. A few studies have examined the effectiveness of mindfulness-based interventions (MBIs) in this context; however, fewer have used an active control group and objective health indicators. Therefore, this study examined the effects of an MBI in comparison to a similarly structured traditional stress management intervention (progressive muscle relaxation, PMR) on health indicators among military personnel. Method: Using a 2 (pre vs. post) × 3 (group: MBI, PMR vs. inactive control group, ICG) experimental mixed design, participants (MBI, n = 118; PMR, n = 55; ICG, n = 156) answered baseline and post-intervention self-reported measures. Physiological parameters were assessed before and after each session. Results: Results showed that MBI is superior to PMR and ICG, leading to higher increases in mindfulness, positive affect, and self-care, and greater decreases in physical complaints. This is also confirmed by objective data. Participants in the MBI demonstrated improved heart rate variability and reduced heart rate, while no change was evident for PMR and ICG. However, both MBI and PMR were equally effective in reducing strain. Conclusions: This study provides further evidence for the effectiveness of MBIs in this specific professional group based on rigorous methodology (comparing to a competing intervention, self-reported and objective measures). MBI is even more effective than PMR as a traditional health intervention in terms of promoting mindfulness, positive affect, and health behavior, as well as reducing complaints. Preregistration: This study is not preregistered.