Exercise prescription and monitoring of heart rate parameters in people with chronic pain: a systematic review

INTRODUCTION: Chronic pain affects over 50 million adults in the United States and is associated with autonomic nervous system dysfunction assessed through measurements of heart rate variability (HRV). While exercise has been shown to improve HRV in healthy individuals, the effects of different exercise protocols in chronic pain populations on HRV remain underexplored. CONTENT: The purpose of this systematic review investigated how exercise interventions influence HRV and pain in individuals with chronic pain. A literature search was conducted in accordance with PRISMA guidelines across four electronic databases. Six randomized controlled trials met the inclusion criteria and were critically appraised for methodological quality. Studies were included if they involved an exercise intervention and reported HRV. If pain was assessed, it was included as an outcome measure. SUMMARY AND OUTLOOK: Six randomized controlled trials were identified with 283 participants. All studies measured HRV, while four reported pain outcomes. Five studies reported significant improvements in HRV following exercise interventions (p <0.05), while findings related to pain outcomes were mixed. Methodological reporting of HRV procedures was generally insufficient. Due to heterogeneity across studies, it remains unclear whether exercise improves pain or HRV sufficiently. While pain outcomes are commonly reported, HRV is the only measure specific to function, and its reliability as a clinical metric in individuals with chronic pain remains uncertain. Limited research across diverse chronic conditions, sexes, and methodological approaches restricts generalizability. This highlights the need for greater methodological rigor and broader inclusion to strengthen the use of HRV metrics in chronic pain populations.